How to effectively identify the oil and water layer has been a difficult problem in the hydrocarbon indicator (HCI). It is generally believed that the oil layer has the characteristics of low frequency enhancement and high frequency attenuation on the frequency spectrum. But in the actual application, the amplitude and frequency characteristics of the thicker water layer are very similar to that of the oil layer, which makes it hard to distinguish one from the other. In this paper, in order to identify the oil and water layer, a new method basis on matching pursuit decomposition (MPD) is proposed. Firstly, the time-frequency analysis of seismic data is carried out though high precision MPD method. Through analyzing the instantaneous amplitude at different frequencies, we consider that the main difference of the oil and water layer in the frequency spectrum is at the high frequency band where the oil layer shows relatively strong amplitude characteristics. Secondly, base on the high frequency resonance (HFR), the high frequency bright spot attribute is calculated from the frequency division data in the high frequency range. In this new attribute, the water layer is suppressed by the strong amplitude of the oil layer. Finally, the results of the HCI are obtained by multiplying the new attribute with the −90 degree phase shift of the seismic data. The forward modeling test and actual application in Bohai oilfield show that the high frequency bright spot method is more effective in suppressing the water layer and identifying thinner oil layers compared with the conventional low frequency and high frequency attenuation methods of HCI.
{"title":"The Application of High Frequency Resonance Based on MPD in the Identification of Oil and Water Layer","authors":"Pingping Zhang, D. Hou, Xugang Ma, Yichuan Wang","doi":"10.2523/IPTC-19329-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19329-MS","url":null,"abstract":"\u0000 How to effectively identify the oil and water layer has been a difficult problem in the hydrocarbon indicator (HCI). It is generally believed that the oil layer has the characteristics of low frequency enhancement and high frequency attenuation on the frequency spectrum. But in the actual application, the amplitude and frequency characteristics of the thicker water layer are very similar to that of the oil layer, which makes it hard to distinguish one from the other. In this paper, in order to identify the oil and water layer, a new method basis on matching pursuit decomposition (MPD) is proposed. Firstly, the time-frequency analysis of seismic data is carried out though high precision MPD method. Through analyzing the instantaneous amplitude at different frequencies, we consider that the main difference of the oil and water layer in the frequency spectrum is at the high frequency band where the oil layer shows relatively strong amplitude characteristics. Secondly, base on the high frequency resonance (HFR), the high frequency bright spot attribute is calculated from the frequency division data in the high frequency range. In this new attribute, the water layer is suppressed by the strong amplitude of the oil layer. Finally, the results of the HCI are obtained by multiplying the new attribute with the −90 degree phase shift of the seismic data. The forward modeling test and actual application in Bohai oilfield show that the high frequency bright spot method is more effective in suppressing the water layer and identifying thinner oil layers compared with the conventional low frequency and high frequency attenuation methods of HCI.","PeriodicalId":11267,"journal":{"name":"Day 3 Thu, March 28, 2019","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82601043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yeen Voon Tan, N. Amiruddin, Hui Ming Li, C. Sim, Shahrizal Abdul Aziz, N. Adnan, M. Mansor, M. A. Anuar, S. Jacobs, Aizuddin Khalid, Ashok Kumar
This paper discusses an alternative study approach with multiple lessons learned from a recent successful infill drilling campaign in a medium-sized brownfield. The team conducted a practical and an optimized subsurface study, including the no-frills classical reservoir engineering and a simple sector model to justify the infill wells. From idea generation to monetization of the barrels, it was fast and cost effective without compromising technical assurance. Results of the infill drilling campaign and lessons learned are discussed in this paper. This is a case study on how a comprehensive understanding of reservoir complexity using creative data integration can be an adequate tool for field development. The results of the campaign demonstrated that an optimized study helps the operator and partners make an efficient investment decision in materializing development opportunities.
{"title":"Unlocking and Materializing Development Opportunities with an Optimized Subsurface Study Approach and Adaptive Execution in a Brownfield","authors":"Yeen Voon Tan, N. Amiruddin, Hui Ming Li, C. Sim, Shahrizal Abdul Aziz, N. Adnan, M. Mansor, M. A. Anuar, S. Jacobs, Aizuddin Khalid, Ashok Kumar","doi":"10.2523/IPTC-19494-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19494-MS","url":null,"abstract":"\u0000 This paper discusses an alternative study approach with multiple lessons learned from a recent successful infill drilling campaign in a medium-sized brownfield. The team conducted a practical and an optimized subsurface study, including the no-frills classical reservoir engineering and a simple sector model to justify the infill wells. From idea generation to monetization of the barrels, it was fast and cost effective without compromising technical assurance.\u0000 Results of the infill drilling campaign and lessons learned are discussed in this paper. This is a case study on how a comprehensive understanding of reservoir complexity using creative data integration can be an adequate tool for field development. The results of the campaign demonstrated that an optimized study helps the operator and partners make an efficient investment decision in materializing development opportunities.","PeriodicalId":11267,"journal":{"name":"Day 3 Thu, March 28, 2019","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77228387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
There is abundant natural gas in Kuqa foreland area of Tarim basin, the reservoir has characteristics of ultra depth(6500m-8000m), high pressure(115MPa-140MPa), high temperature(170°C-190°C) and complex corrosive medium, which bring well integrity high challenge. There are 52 production wells in the Kuqa foreland basin in 2012. The 16 wells of these production wells exist sustained casing pressure(SCP). The SCP wells caused by the tubing string failure is 61%. Since 2012, in order to build safe well barrier and achieve scientific production management, consider all important periods of drilling, well testing, well completion and production in well full life cycle. the design methods of the four main well barrier components(casing string, cement, tubing string, well head) are optimized. A set of technology for well barrier quality control, well maintenance and well production management is formed. Finally, the key technology of full life cycle well integrity for ultra depth, HPHT gas well is formed. In view of the large angle of bedding, well deviation controlled difficultly, and coexistence of high pressure saline aquifer and week bed in one open hole section which lead to serious casing wear and poor cement stone, the vertical well drilling technology, the collapse resistance casing design methods, the casing wear preventing measures, negative pressure test method and high temperature, high density cementing technology are completed. These technologies improve the safety of casing string and the quality of cement. Considering the extreme working conditions(the partial pressure of CO2 is beyond 2MPa, The content of chlorine is about 80000mg/L, acid job, 136MPa pump pressure in well head)of tubing string, material selection method, triaxial stress analysis method, quality control technology for tubing string is optimized. The failure ratio of tubing string reduced from 50% in 2013 to zero in 2017. Referencing API RP 90-2 and IOS16530-2, a special calculation method for annulus pressure management is formed, which include minimum operation pressure and maximum allowable pressure for different annulus. Then a risk assessment system is established. The SCP wells is controlled less than 22% in the condition of increasing number of high pressure gas wells. Based on the research introduced above, China's first set of well integrity specification series is completed. The integrity specification series include the well integrity guide, the well integrity design and the well integrity management for high temperature high pressure and high sulfur gas. These results effectively support safty in production for high pressure gas field in Tarim basin, and will promote the well integrity level in the same kind of oilfield.
塔里木盆地库车前陆地区天然气储量丰富，储层具有超深(6500m ~ 8000m)、高压(115mpa ~ 140mpa)、高温(170℃~ 190℃)、复杂腐蚀介质等特点，对井的完整性提出了很高的挑战。库车前陆盆地2012年生产井52口。这些生产井中有16口井存在持续套管压力(SCP)。由管柱失效引起的SCP井占61%。从2012年开始，为了建立安全井障，实现科学的生产管理，在井全生命周期中考虑钻井、试井、完井和生产的所有重要时期。优化了4个主要井障部件(套管柱、水泥、管柱、井口)的设计方法。形成了一套井眼质量控制、井眼维护和井眼生产管理的技术体系。最后，形成了超深高温气井全生命周期井完整性的关键技术。针对层理角度大、井斜控制困难、同一裸眼段高压盐水层与周层共存导致套管磨损严重、固井效果差的问题，完成了直井钻井技术、抗塌套管设计方法、防套管磨损措施、负压试验方法和高温高密度固井技术。这些技术提高了套管柱的安全性和固井质量。针对管柱的极端工况(CO2分压大于2MPa、氯含量80000mg/L左右、酸作业、井口泵压136MPa)，对管柱的选材方法、三轴应力分析方法、质量控制工艺进行了优化。管柱的故障率从2013年的50%降至2017年的零。参考API RP 90-2和IOS16530-2，形成了环空压力管理的专用计算方法，包括不同环空的最小操作压力和最大允许压力。然后建立了风险评估体系。在高压气井数量不断增加的情况下，SCP井控制在22%以下。在此基础上，完成了国内第一套井完整性规范系列。完整性规范系列包括高温高压高硫气体井完整性指南、井完整性设计和井完整性管理。这些成果有效地支撑了塔里木盆地高压气田的安全生产，提高了同类型油田的井完整性水平。
{"title":"Research and Practice of Full Life Cycle Well Integrity in HTHP Well, Tarim Oilfield","authors":"Hongtao Liu, Lihu Cao, Jun-feng Xie, Xiangtong Yang, Nu Zeng, Xuesong Zhang, Fei Chen","doi":"10.2523/IPTC-19403-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19403-MS","url":null,"abstract":"\u0000 There is abundant natural gas in Kuqa foreland area of Tarim basin, the reservoir has characteristics of ultra depth(6500m-8000m), high pressure(115MPa-140MPa), high temperature(170°C-190°C) and complex corrosive medium, which bring well integrity high challenge. There are 52 production wells in the Kuqa foreland basin in 2012. The 16 wells of these production wells exist sustained casing pressure(SCP). The SCP wells caused by the tubing string failure is 61%.\u0000 Since 2012, in order to build safe well barrier and achieve scientific production management, consider all important periods of drilling, well testing, well completion and production in well full life cycle. the design methods of the four main well barrier components(casing string, cement, tubing string, well head) are optimized. A set of technology for well barrier quality control, well maintenance and well production management is formed. Finally, the key technology of full life cycle well integrity for ultra depth, HPHT gas well is formed.\u0000 In view of the large angle of bedding, well deviation controlled difficultly, and coexistence of high pressure saline aquifer and week bed in one open hole section which lead to serious casing wear and poor cement stone, the vertical well drilling technology, the collapse resistance casing design methods, the casing wear preventing measures, negative pressure test method and high temperature, high density cementing technology are completed. These technologies improve the safety of casing string and the quality of cement. Considering the extreme working conditions(the partial pressure of CO2 is beyond 2MPa, The content of chlorine is about 80000mg/L, acid job, 136MPa pump pressure in well head)of tubing string, material selection method, triaxial stress analysis method, quality control technology for tubing string is optimized. The failure ratio of tubing string reduced from 50% in 2013 to zero in 2017. Referencing API RP 90-2 and IOS16530-2, a special calculation method for annulus pressure management is formed, which include minimum operation pressure and maximum allowable pressure for different annulus. Then a risk assessment system is established. The SCP wells is controlled less than 22% in the condition of increasing number of high pressure gas wells.\u0000 Based on the research introduced above, China's first set of well integrity specification series is completed. The integrity specification series include the well integrity guide, the well integrity design and the well integrity management for high temperature high pressure and high sulfur gas. These results effectively support safty in production for high pressure gas field in Tarim basin, and will promote the well integrity level in the same kind of oilfield.","PeriodicalId":11267,"journal":{"name":"Day 3 Thu, March 28, 2019","volume":"365 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80331664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Waterflood (WF) is the main drive mechanism of North Kuwait reservoirs. Different development strategies has been adopted to develop a giant carbonate reservoir in the asset. Irregular scheme of WF has been implemented in the last 5 years which made it challenging to properly evaluate the WF performance. This paper presents both numerical and analytical approaches to assess the current performance of the waterflood in this reservoir. The first method uses actual production and injection data to generate traditional waterflood plots such WOR vs. Np, injection throughput, VRR and other diagnostics. The second approach uses the numerical model to understand the fluid movements in terms of production and water injection. A high resolution model is used to know about the horizontal producers and injectors WF scheme. Streamline model tool is used to understand how the injectors impact their surrounding producers. Injector's efficiency, allocation factors and reservoir sweep efficiency are calculated using the simulation model. Both approaches are compared to have a better evaluation of the waterflood. When the waterflood started, a regular i-9 spot patterns was the way to develop the reservoir. The heterogeneity of the reservoir was observed clearly in the different performance of each pattern. Also, high permeability layer (thief zone) has adversely affected the reservoir performance during WF. The sharp increase of water cut with very low corresponding recovery factor triggered a paradigm shift in developing this waterflooded reservoir. Injecting in lower layers and producing in upper layers (horizontal wells) was the next stage. This brought a great challenge to assess the performance of this WF scheme. Evaluating such a development strategy remains a achallenge.
{"title":"Numerical and Analytical Waterflood Evaluation of North Kuwait Giant Carbonate Reservoir","authors":"B. Al-Otaibi, Sadok Lamine","doi":"10.2523/IPTC-19480-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19480-MS","url":null,"abstract":"\u0000 Waterflood (WF) is the main drive mechanism of North Kuwait reservoirs. Different development strategies has been adopted to develop a giant carbonate reservoir in the asset. Irregular scheme of WF has been implemented in the last 5 years which made it challenging to properly evaluate the WF performance. This paper presents both numerical and analytical approaches to assess the current performance of the waterflood in this reservoir.\u0000 The first method uses actual production and injection data to generate traditional waterflood plots such WOR vs. Np, injection throughput, VRR and other diagnostics.\u0000 The second approach uses the numerical model to understand the fluid movements in terms of production and water injection. A high resolution model is used to know about the horizontal producers and injectors WF scheme. Streamline model tool is used to understand how the injectors impact their surrounding producers. Injector's efficiency, allocation factors and reservoir sweep efficiency are calculated using the simulation model.\u0000 Both approaches are compared to have a better evaluation of the waterflood.\u0000 When the waterflood started, a regular i-9 spot patterns was the way to develop the reservoir. The heterogeneity of the reservoir was observed clearly in the different performance of each pattern. Also, high permeability layer (thief zone) has adversely affected the reservoir performance during WF.\u0000 The sharp increase of water cut with very low corresponding recovery factor triggered a paradigm shift in developing this waterflooded reservoir. Injecting in lower layers and producing in upper layers (horizontal wells) was the next stage. This brought a great challenge to assess the performance of this WF scheme. Evaluating such a development strategy remains a achallenge.","PeriodicalId":11267,"journal":{"name":"Day 3 Thu, March 28, 2019","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87446329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shusheng Guo, Yongde Gao, F. Gui, Shanshan Wang, S. Bordoloi, S. Ong, Chao Du, Shiyue Wang
The drilling in Wushi Sag of the Beibu Gulf appears to be problematic with frequent pack-off, tight-hole and stuck-pipe events as well as kicks and losses occurring in different wells. It is of great importance to find out the main cause or causes of these problems so that proper methods and techniques can be utilized to mitigate the problems and reduce the drilling non-productive time (NPT). A series of drilled wells were reviewed to identify the key wells to be used for the geomechanical modelling and to help with understanding the drilling problems. One of the outcomes of the detailed geomechanical analysis was the realization that the stresses and rock behaviors are mainly affected and controlled by the structures. Wushi Sag can be divided into four structural areas: subsag-steep slope in the south, central inverted structure area, north slope and strike-slip faulting belt in the west. As a consequence of the complex structures, the formation depth varies greatly while some formations are absent or incomplete in some wells due to the well-developed high-angled faults. An outcome of the study was the understanding that formation pressures are different in every structural area and are controlled by structural location and burial depth. The main overpressure generating mechanism was found to be type-II fluid expansion caused by either hydrocarbon generation or thermal effects, which can be well correlated to the oil window threshold in the area. Under-compaction may also play a role in some cases, but the overpressure caused by this mechanism is usually low in magnitude. Rock properties vary across the Sag while wells are hard to correlate with each other in different structural areas. The stress conditions appear to be different in each area although the main stress regime is strike-slip with the strike-slip faulting belt in the west having the highest stress ratio. Due to the complexity of the pressure distribution, lateral formation changes and different stress conditions, improper mud weights and casing designs were used in some earlier wells, which likely led to the types of drilling problems listed above. Wells with severe instability problems were generally drilled with lower mud weights compared to the wells with lesser problems. Wells with both pack-off/tight holes and fluid losses usually have surface or intermittent casing shoes set too shallow while not preparing for the steep pressure ramp in deeper formations. Based on the problem diagnostics and geomechanical analyses, recommendations were made to help with the drilling of future wells by mitigating drilling-related instability problems. A series of wells were drilled successfully following the recommendations with all the possible risks properly understood and mitigated.
{"title":"Full Scale Geomechanics Review Assisting Drilling Risk Mitigation in Wushi Sag, Beibu Gulf, China","authors":"Shusheng Guo, Yongde Gao, F. Gui, Shanshan Wang, S. Bordoloi, S. Ong, Chao Du, Shiyue Wang","doi":"10.2523/IPTC-19274-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19274-MS","url":null,"abstract":"\u0000 The drilling in Wushi Sag of the Beibu Gulf appears to be problematic with frequent pack-off, tight-hole and stuck-pipe events as well as kicks and losses occurring in different wells. It is of great importance to find out the main cause or causes of these problems so that proper methods and techniques can be utilized to mitigate the problems and reduce the drilling non-productive time (NPT).\u0000 A series of drilled wells were reviewed to identify the key wells to be used for the geomechanical modelling and to help with understanding the drilling problems. One of the outcomes of the detailed geomechanical analysis was the realization that the stresses and rock behaviors are mainly affected and controlled by the structures. Wushi Sag can be divided into four structural areas: subsag-steep slope in the south, central inverted structure area, north slope and strike-slip faulting belt in the west. As a consequence of the complex structures, the formation depth varies greatly while some formations are absent or incomplete in some wells due to the well-developed high-angled faults.\u0000 An outcome of the study was the understanding that formation pressures are different in every structural area and are controlled by structural location and burial depth. The main overpressure generating mechanism was found to be type-II fluid expansion caused by either hydrocarbon generation or thermal effects, which can be well correlated to the oil window threshold in the area. Under-compaction may also play a role in some cases, but the overpressure caused by this mechanism is usually low in magnitude. Rock properties vary across the Sag while wells are hard to correlate with each other in different structural areas. The stress conditions appear to be different in each area although the main stress regime is strike-slip with the strike-slip faulting belt in the west having the highest stress ratio.\u0000 Due to the complexity of the pressure distribution, lateral formation changes and different stress conditions, improper mud weights and casing designs were used in some earlier wells, which likely led to the types of drilling problems listed above. Wells with severe instability problems were generally drilled with lower mud weights compared to the wells with lesser problems. Wells with both pack-off/tight holes and fluid losses usually have surface or intermittent casing shoes set too shallow while not preparing for the steep pressure ramp in deeper formations. Based on the problem diagnostics and geomechanical analyses, recommendations were made to help with the drilling of future wells by mitigating drilling-related instability problems. A series of wells were drilled successfully following the recommendations with all the possible risks properly understood and mitigated.","PeriodicalId":11267,"journal":{"name":"Day 3 Thu, March 28, 2019","volume":"80 2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87978036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The igneous reservoir of Shahejie formation in eastern sag of Liaohe depression is characterized by complex geological environment, variable lithology and high heterogeneity. Reservoir evaluation is difficult only based on conventional logs due to complex lithology and pore structures. Effective igneous reservoirs were identified and reservoir controlling factors were analyzed based on effective porosity calculation, pore structure analysis, lithology identification, lithofacies analysis, fracture evaluation and heterogeneity analysis by combing nuclear magnetic resonance data, micro-resistivity image data, conventional logs as well as mud logging data. Based on our study, the igneous reservoirs in the study area are more related with effective porosity and pore connectivity, and less related with fractures. Good reservoirs are mainly distributed on the top part of explosive facies and effusive facies, where lithologies are mainly Trachyte, volcanic breccia and breccia-bearing tuff. The weathering leaching process is quite important for igneous reservoirs, but the reservoir qulity would not be good if the weathering process is too strong as it will lead to low effective porosity. The accuracy of igneous reservoir evaluation gets improved a lot by this integrated approach and the conclusion from this study will help to optimize igneous reservoire exploration plan.
{"title":"Effective Igneous Reservoir Identification and Controlling Factor Analysis in Eastern Sag of Liaohe Depression, China","authors":"Zhenhua Hu, Shenqin Zhang, Fangfang Wu, Xunqi Liu, Jinlong Wu, Shenzhuan Li, Yuxi Wang, Xianran Zhao, Haipeng Zhao","doi":"10.2523/IPTC-19442-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19442-MS","url":null,"abstract":"\u0000 The igneous reservoir of Shahejie formation in eastern sag of Liaohe depression is characterized by complex geological environment, variable lithology and high heterogeneity. Reservoir evaluation is difficult only based on conventional logs due to complex lithology and pore structures. Effective igneous reservoirs were identified and reservoir controlling factors were analyzed based on effective porosity calculation, pore structure analysis, lithology identification, lithofacies analysis, fracture evaluation and heterogeneity analysis by combing nuclear magnetic resonance data, micro-resistivity image data, conventional logs as well as mud logging data.\u0000 Based on our study, the igneous reservoirs in the study area are more related with effective porosity and pore connectivity, and less related with fractures. Good reservoirs are mainly distributed on the top part of explosive facies and effusive facies, where lithologies are mainly Trachyte, volcanic breccia and breccia-bearing tuff. The weathering leaching process is quite important for igneous reservoirs, but the reservoir qulity would not be good if the weathering process is too strong as it will lead to low effective porosity.\u0000 The accuracy of igneous reservoir evaluation gets improved a lot by this integrated approach and the conclusion from this study will help to optimize igneous reservoire exploration plan.","PeriodicalId":11267,"journal":{"name":"Day 3 Thu, March 28, 2019","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84906245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yijin Zeng, Yuan Gao, Shiming Zhou, Q. Tao, Sang Laiyu, Guangguo Yang, Peiqing Lu
Many challenges exist in ultra-deep high-temperature and high-pressure gas well cementing, such as, high-temperature, active gas layer, narrow density window, and seal integrity failure of cement sheath, which brings huge difficulties in anti-gas channeling cementing. By selecting the nano-liquid silicon and latex anti-gas channeling agents, and synergistically enhancing the anti-gas channeling performance of cement slurry, the mechanical properties of cement set is improved; by optimizing the compounding and dosage of silicon powder with different particle sizes, the high-temperature stability of cement set is enhanced. Via the selection of inorganic fiber cracking-prevention and plugging system, the crack propagation is inhibited, and the leakage resistance of cement slurry and the impact resistance of cement set are improved. Hence, a high-temperature resistant latex anti-gas channeling cement slurry system was developed. The cement slurry system has the following properties: API water loss of <50 mL at 180 °C, SPN value of <1, cement set compressive strength of 39.3 MPa under 200 °C×21 MPa×60 d, Young's modulus of 6.9 GPa, gas layer permeability of 0.004×10-3 μm2, and its comprehensive mechanical properties are better than that on the 30th day. The cement sheath seal integrity evaluation shows that the 26.7 mm sheath can achieve an effective seal effect under the cyclic loading process (peak pressure is 90 MPa). Combined with the staged gas layer stability prediction, the pressure management cementing technology under unsteady conditions was proposed, which solves the problems of gas channeling and leakage prevention in ultra-deep high-temperature and high-pressure reservoirs with enriched fracture-cavity. The anti-gas channeling cementing technology has been used in the Shunnan and Shunbei plays of Sinopec Northwest Oilfield Company, and it can provide references for the cementing of similar gas wells.
{"title":"Anti-Gas Channeling Cementing Technology for Ultra-Deep High Temperature and High Pressure Gas Wells","authors":"Yijin Zeng, Yuan Gao, Shiming Zhou, Q. Tao, Sang Laiyu, Guangguo Yang, Peiqing Lu","doi":"10.2523/IPTC-19109-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19109-MS","url":null,"abstract":"\u0000 Many challenges exist in ultra-deep high-temperature and high-pressure gas well cementing, such as, high-temperature, active gas layer, narrow density window, and seal integrity failure of cement sheath, which brings huge difficulties in anti-gas channeling cementing. By selecting the nano-liquid silicon and latex anti-gas channeling agents, and synergistically enhancing the anti-gas channeling performance of cement slurry, the mechanical properties of cement set is improved; by optimizing the compounding and dosage of silicon powder with different particle sizes, the high-temperature stability of cement set is enhanced. Via the selection of inorganic fiber cracking-prevention and plugging system, the crack propagation is inhibited, and the leakage resistance of cement slurry and the impact resistance of cement set are improved. Hence, a high-temperature resistant latex anti-gas channeling cement slurry system was developed. The cement slurry system has the following properties: API water loss of <50 mL at 180 °C, SPN value of <1, cement set compressive strength of 39.3 MPa under 200 °C×21 MPa×60 d, Young's modulus of 6.9 GPa, gas layer permeability of 0.004×10-3 μm2, and its comprehensive mechanical properties are better than that on the 30th day. The cement sheath seal integrity evaluation shows that the 26.7 mm sheath can achieve an effective seal effect under the cyclic loading process (peak pressure is 90 MPa). Combined with the staged gas layer stability prediction, the pressure management cementing technology under unsteady conditions was proposed, which solves the problems of gas channeling and leakage prevention in ultra-deep high-temperature and high-pressure reservoirs with enriched fracture-cavity. The anti-gas channeling cementing technology has been used in the Shunnan and Shunbei plays of Sinopec Northwest Oilfield Company, and it can provide references for the cementing of similar gas wells.","PeriodicalId":11267,"journal":{"name":"Day 3 Thu, March 28, 2019","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87775949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jian Zhao, J. He, Yong He, P. Sun, Yanbo Li, Hongliang Chen, Shengliang Zhang, Y. Guo
The poor quality of resources, low utilization of reserves,high investment in capacity building are the main problems faced in low permeability reservoir in Jilin Oilfield.The objective of this research is to form a intensive drilling model of large platforms which can improve the drilling quality,efficiency and management level. By applying this model,we can increase the single well production,block recovery rate and reduce the production construction investments,the development and production costs in low permeability oilfield. This research based on the production capacity construction in the Jilin Oilfield.This drilling model is different from the traditional model which is inefficient and the investments are higher.Our main procedures included the drilling plan optimization,intensive drilling application,efficient drilling technology application and drilling production management optimization. From 2015 to 2017,we have applied this drilling model successfully in Jilin Oilfield. 1 Drilling Plan Optimization Technology The single well and small platforms are commonly used in the reservoir development of Jilin oilfield. Because of the low oil price,we changed our train of thought from traditional development mode to intensive drilling model of large platforms large platforms.It can reduce the land occupation area of well sites,reduce integrated management costs,and improve economical benefits of development effectively.By applying the lowest costs of investment principles,drilling engineering formed integrated drilling plan optimization technology which satisfied the requirements of geological deployment,fracturing and lifting,ground engineering,intensive drilling,economical development.It formed the platform size optimization technology that determined the most economical well number of the platforms.The oil field development investments contain 6 main parts,including drilling engineering,mud log engineering,logging engineering,oil recovery engineering,surface construction engineering and land occupation investments.With the increasing of the platform scale,the investments of drilling engineering increases,because the costs of drilling bits,drilling mud,casing,cement increase,which caused by the increasing of the well depth.The increasing of mud log engineering and logging engineering are not obviously which can be not considered.The investments of oil recovery engineering increases,because the costs of oil lifting,oil pumping machine,well perforation,water flooding increase,which caused by the increasing of the well depth.The investments of surface construction engineering and land occupation investments decrease because of the reduction of well sites pipe network and ground roads.In a word,the investments of drilling and oil recovery engineering increase and the investments of surface construction engineering and land occupation decrease with the increase of platform scale,which exists the optimum interval.By building di
{"title":"Research and Application on Intensive Drilling Model of Large Platforms","authors":"Jian Zhao, J. He, Yong He, P. Sun, Yanbo Li, Hongliang Chen, Shengliang Zhang, Y. Guo","doi":"10.2523/IPTC-19374-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19374-MS","url":null,"abstract":"\u0000 \u0000 \u0000 The poor quality of resources, low utilization of reserves,high investment in capacity building are the main problems faced in low permeability reservoir in Jilin Oilfield.The objective of this research is to form a intensive drilling model of large platforms which can improve the drilling quality,efficiency and management level. By applying this model,we can increase the single well production,block recovery rate and reduce the production construction investments,the development and production costs in low permeability oilfield.\u0000 \u0000 \u0000 \u0000 This research based on the production capacity construction in the Jilin Oilfield.This drilling model is different from the traditional model which is inefficient and the investments are higher.Our main procedures included the drilling plan optimization,intensive drilling application,efficient drilling technology application and drilling production management optimization. From 2015 to 2017,we have applied this drilling model successfully in Jilin Oilfield.\u0000 \u0000 \u0000 \u0000 1 Drilling Plan Optimization Technology\u0000 The single well and small platforms are commonly used in the reservoir development of Jilin oilfield. Because of the low oil price,we changed our train of thought from traditional development mode to intensive drilling model of large platforms large platforms.It can reduce the land occupation area of well sites,reduce integrated management costs,and improve economical benefits of development effectively.By applying the lowest costs of investment principles,drilling engineering formed integrated drilling plan optimization technology which satisfied the requirements of geological deployment,fracturing and lifting,ground engineering,intensive drilling,economical development.It formed the platform size optimization technology that determined the most economical well number of the platforms.The oil field development investments contain 6 main parts,including drilling engineering,mud log engineering,logging engineering,oil recovery engineering,surface construction engineering and land occupation investments.With the increasing of the platform scale,the investments of drilling engineering increases,because the costs of drilling bits,drilling mud,casing,cement increase,which caused by the increasing of the well depth.The increasing of mud log engineering and logging engineering are not obviously which can be not considered.The investments of oil recovery engineering increases,because the costs of oil lifting,oil pumping machine,well perforation,water flooding increase,which caused by the increasing of the well depth.The investments of surface construction engineering and land occupation investments decrease because of the reduction of well sites pipe network and ground roads.In a word,the investments of drilling and oil recovery engineering increase and the investments of surface construction engineering and land occupation decrease with the increase of platform scale,which exists the optimum interval.By building di","PeriodicalId":11267,"journal":{"name":"Day 3 Thu, March 28, 2019","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74263376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Apollinaris Stefanus Leo Anis, Zilman Syarif, A. Setiawan, A. Hidayat, A. S. Murtani
Ujung Pangkah Field which located at offshore East Java Indonesia, is known for its challenging nature from geological, reservoir and drilling perspectives. Drilling experiences in this area shows severe wellbore instability in overburden shale and in fractured carbonate reservoir. Hydrocarbon production directly exacerbate drilling problems and production issues that were not expected came earlier than predicted, for example early water breakthrough. At least two or three operators facing similar severe wellbore instability problems in the area. Due to the complexity of subsurface systems and coupled interactions between depletion and stresses, the present-day stress state in Ujung Pangkah Field which have undergone production will be different from the pre-production stress state. Therefore, a comprehensive analysis will require numerical modelling involving coupling of 3D geomechanical model with fluid flow during production operations from dynamic model. Present-day stress state is subsequently used for wellbore stability analysis of planned development wells in Ujung Pangkah Field. Investigation of the behavior of natural fractured reservoir during depletion and its impact to reservoir management is also attempted. Two-way coupling of geomechanic and dynamic models were conducted whereby porosity and permeability update due to production were simulated based on uniaxial pore volume compressibility tests. Hence, porosity and permeability of fractures are not considered static anymore but dynamic due to stresses changes and production. The result of coupled simulation is able to reduce wellbore instabilities significantly in the planned well. The stable mud weight windows for planned wells are extracted from the model. The stable mud weight window in the reservoir interval is narrow to no stable drilling window in all the planned wells due to depletion. In general, the preferred direction to drill, requiring lowest mud weights, is in the direction of minimum horizontal stress which in this case is Northwest-Southeast (NW-SE). However, it was found that azimuthal dependency of mud weight is insignificant due to low horizontal stress anisotropy. Reservoir compaction and sea-bed subsidence were also calculated using the outputs from the model. The result is useful for completion and platform integrity.
{"title":"4D Geomechanical Simulation in Fractured Carbonate Reservoir for Optimum Well Construction and Reservoir Management, Case Study in Offshore East Java Area","authors":"Apollinaris Stefanus Leo Anis, Zilman Syarif, A. Setiawan, A. Hidayat, A. S. Murtani","doi":"10.2523/IPTC-19570-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19570-MS","url":null,"abstract":"\u0000 Ujung Pangkah Field which located at offshore East Java Indonesia, is known for its challenging nature from geological, reservoir and drilling perspectives. Drilling experiences in this area shows severe wellbore instability in overburden shale and in fractured carbonate reservoir. Hydrocarbon production directly exacerbate drilling problems and production issues that were not expected came earlier than predicted, for example early water breakthrough. At least two or three operators facing similar severe wellbore instability problems in the area.\u0000 Due to the complexity of subsurface systems and coupled interactions between depletion and stresses, the present-day stress state in Ujung Pangkah Field which have undergone production will be different from the pre-production stress state. Therefore, a comprehensive analysis will require numerical modelling involving coupling of 3D geomechanical model with fluid flow during production operations from dynamic model. Present-day stress state is subsequently used for wellbore stability analysis of planned development wells in Ujung Pangkah Field. Investigation of the behavior of natural fractured reservoir during depletion and its impact to reservoir management is also attempted. Two-way coupling of geomechanic and dynamic models were conducted whereby porosity and permeability update due to production were simulated based on uniaxial pore volume compressibility tests. Hence, porosity and permeability of fractures are not considered static anymore but dynamic due to stresses changes and production.\u0000 The result of coupled simulation is able to reduce wellbore instabilities significantly in the planned well. The stable mud weight windows for planned wells are extracted from the model. The stable mud weight window in the reservoir interval is narrow to no stable drilling window in all the planned wells due to depletion. In general, the preferred direction to drill, requiring lowest mud weights, is in the direction of minimum horizontal stress which in this case is Northwest-Southeast (NW-SE). However, it was found that azimuthal dependency of mud weight is insignificant due to low horizontal stress anisotropy.\u0000 Reservoir compaction and sea-bed subsidence were also calculated using the outputs from the model. The result is useful for completion and platform integrity.","PeriodicalId":11267,"journal":{"name":"Day 3 Thu, March 28, 2019","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77419348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In today's fast paced and challenging oil industry, the need of faster evaluation studies for quick generation of field development plan (FDP) is becoming more crucial to remain competitive. Field's geological and structural complexity, uncertainty of production data adds to the challenges. Traditional approach of building dynamic mesh models carrying out numerical simulation to history match, then predict has always remained time consuming in large mature fields. The ‘B’ field in Peninsular Malaysia is a mature clastic with stacked reservoirs having a huge gas cap with moderate aquifer. Significant production over last 30+ years led to uneven movement of the gas cap and also of the edge aquifer leading to possibility of bypassed oil. The updated dynamic model could not match the preferential gas cap movement, thus failed to match the high GOR of downdip wells and also unable to match high watercut of certain updip wells. To identify the areas of bypassed oil thus is a significant challenge with the current dynamic model. New engineering tools of polygon balancing, material balance, normalized EUR bubbles were used with the 3D static model volume and the facies understanding. The uncertainties and risks were also identified and clear measurable methods were proposed to address the uncertainties and reduce the risks. Very detailed decision tree with clear data gathering plan to drill successive optimum wells have been planned during the campaign. This paper details the new engineering tools used to delineate and quantify the bypassed oil in these huge clastic reservoir with preferential gas and water movement, unable to be history matched by the dynamic model. It explains the engineering methods applied to identify and quantify the 10 infill wells proposed for the development campaign. To reduce risks, this paper would also explain the blind testing that was carried out on for this new reservoir engineering analysis tool by deriving the infill potentials of the previous campaign (4 years back) by the same method. The paper details how robust technical development plans were generated having infill well locations and reserve determination. This paper will also demonstrate the classic "Do-Learn-Adapt" strategy through its infill wells prioritization & ranking, subsurface de-risking analysis, data acquisition and mitigations plans.
{"title":"An Innovative Reservoir Engineering Method to Identify Bypassed Oil and Derisk the Further Development of a Complex Mature Field in Offshore, Malaysia","authors":"D. Mandal, N. Musani, N. I. Mohmad","doi":"10.2523/IPTC-19182-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19182-MS","url":null,"abstract":"\u0000 In today's fast paced and challenging oil industry, the need of faster evaluation studies for quick generation of field development plan (FDP) is becoming more crucial to remain competitive. Field's geological and structural complexity, uncertainty of production data adds to the challenges. Traditional approach of building dynamic mesh models carrying out numerical simulation to history match, then predict has always remained time consuming in large mature fields.\u0000 The ‘B’ field in Peninsular Malaysia is a mature clastic with stacked reservoirs having a huge gas cap with moderate aquifer. Significant production over last 30+ years led to uneven movement of the gas cap and also of the edge aquifer leading to possibility of bypassed oil. The updated dynamic model could not match the preferential gas cap movement, thus failed to match the high GOR of downdip wells and also unable to match high watercut of certain updip wells. To identify the areas of bypassed oil thus is a significant challenge with the current dynamic model. New engineering tools of polygon balancing, material balance, normalized EUR bubbles were used with the 3D static model volume and the facies understanding. The uncertainties and risks were also identified and clear measurable methods were proposed to address the uncertainties and reduce the risks. Very detailed decision tree with clear data gathering plan to drill successive optimum wells have been planned during the campaign.\u0000 This paper details the new engineering tools used to delineate and quantify the bypassed oil in these huge clastic reservoir with preferential gas and water movement, unable to be history matched by the dynamic model. It explains the engineering methods applied to identify and quantify the 10 infill wells proposed for the development campaign. To reduce risks, this paper would also explain the blind testing that was carried out on for this new reservoir engineering analysis tool by deriving the infill potentials of the previous campaign (4 years back) by the same method.\u0000 The paper details how robust technical development plans were generated having infill well locations and reserve determination. This paper will also demonstrate the classic \"Do-Learn-Adapt\" strategy through its infill wells prioritization & ranking, subsurface de-risking analysis, data acquisition and mitigations plans.","PeriodicalId":11267,"journal":{"name":"Day 3 Thu, March 28, 2019","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81373019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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