The key factor for characterizing unconventional shale reservoirs is the total organic carbon (TOC). TOC is estimated conventionally by analysis cores samples which requires extensive lab work, thus it is time-consuming and costly. Several empirical models are suggested to estimate the TOC indirectly using conventional well logs. These models assume the TOC and well logs are linearly related, this assumption significantly reduces the TOC estimation accuracy. In this work, the design parameters of the artificial neural network (ANN) were optimized using self-adaptive differential evolution (SaDE) method to effectively predict the TOC from the conventional well log data. A new correlation for TOC calculation was developed, which is based on the optimized SaDE-ANN model. 460 data points of different well logs from Barnett formation were used to learn and validate the optimized SaDE-ANN model. The predictability of the SaDE-ANN correlation was compared with the available correlations for predicting the TOC using 29 data point from Duvernay formation. The TOC was estimated using the optimized SaDE-ANN model with an average absolute percentage error (AAPE) and correlation coefficient (R) of 6% and 0.98, respectively. The SaDE-ANN correlation developed for TOC prediction outperformed the recent models suggested by Wang et al. (2016) and Mahmoud et al. (2017). The new empirical equation reduced the AAPE in predicting the TOC by 67% compared to Mahmoud et al. (2017) model in Duvernay formation.
总有机碳(TOC)是表征非常规页岩储层的关键因素。TOC通常是通过分析岩心样品来估计的，这需要大量的实验室工作，因此既耗时又昂贵。提出了几种利用常规测井资料间接估算TOC的经验模型。这些模型假设TOC和测井曲线是线性相关的，这种假设大大降低了TOC估计的精度。采用自适应差分进化(SaDE)方法对人工神经网络(ANN)的设计参数进行优化，从常规测井资料中有效预测TOC。在优化的SaDE-ANN模型的基础上，建立了一种新的TOC计算关联。利用Barnett地层的460个不同测井数据点来学习和验证优化后的SaDE-ANN模型。将SaDE-ANN相关性的可预测性与利用Duvernay地层29个数据点预测TOC的可用相关性进行了比较。利用优化后的SaDE-ANN模型估计TOC，平均绝对百分比误差(AAPE)和相关系数(R)分别为6%和0.98。用于TOC预测的SaDE-ANN相关性优于Wang等人(2016)和Mahmoud等人(2017)提出的最新模型。与Mahmoud et al.(2017)的Duvernay地层模型相比，新的经验方程将预测TOC的AAPE降低了67%。
{"title":"New Artificial Neural Network Model for Predicting the TOC from Well Logs","authors":"A. Sultan","doi":"10.2118/194716-MS","DOIUrl":"https://doi.org/10.2118/194716-MS","url":null,"abstract":"\u0000 The key factor for characterizing unconventional shale reservoirs is the total organic carbon (TOC). TOC is estimated conventionally by analysis cores samples which requires extensive lab work, thus it is time-consuming and costly. Several empirical models are suggested to estimate the TOC indirectly using conventional well logs. These models assume the TOC and well logs are linearly related, this assumption significantly reduces the TOC estimation accuracy.\u0000 In this work, the design parameters of the artificial neural network (ANN) were optimized using self-adaptive differential evolution (SaDE) method to effectively predict the TOC from the conventional well log data. A new correlation for TOC calculation was developed, which is based on the optimized SaDE-ANN model. 460 data points of different well logs from Barnett formation were used to learn and validate the optimized SaDE-ANN model. The predictability of the SaDE-ANN correlation was compared with the available correlations for predicting the TOC using 29 data point from Duvernay formation.\u0000 The TOC was estimated using the optimized SaDE-ANN model with an average absolute percentage error (AAPE) and correlation coefficient (R) of 6% and 0.98, respectively. The SaDE-ANN correlation developed for TOC prediction outperformed the recent models suggested by Wang et al. (2016) and Mahmoud et al. (2017). The new empirical equation reduced the AAPE in predicting the TOC by 67% compared to Mahmoud et al. (2017) model in Duvernay formation.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74337685","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}
Alfredo Arevalo, A. Buenrostro, Mauricio Espinosa, A. Harbi
Tight sandstone reservoirs under this project have been a challenge to stimulate due the high breakdown pressure required to create the fracture, and a challenge on production recovery due fast decline observed in some of these wells. Exploring Multi Stage Fracturing completion in horizontal wells in these tight sandstone reservoirs increases the overall reservoir exposure to stimulation treatments by Hydraulic Fracturing, and expects a better and longer production performance. This paper evaluates the recently deployed Open Hole – Multi Stage Fracturing completions (OH-MSF) over tight sandstone gas reservoirs.
{"title":"Multi Stage - Open Hole Completions: Continuous Successes in Placing Multiple Fractures in a Single Tight Gas Sandstone","authors":"Alfredo Arevalo, A. Buenrostro, Mauricio Espinosa, A. Harbi","doi":"10.2118/194908-MS","DOIUrl":"https://doi.org/10.2118/194908-MS","url":null,"abstract":"\u0000 Tight sandstone reservoirs under this project have been a challenge to stimulate due the high breakdown pressure required to create the fracture, and a challenge on production recovery due fast decline observed in some of these wells. Exploring Multi Stage Fracturing completion in horizontal wells in these tight sandstone reservoirs increases the overall reservoir exposure to stimulation treatments by Hydraulic Fracturing, and expects a better and longer production performance. This paper evaluates the recently deployed Open Hole – Multi Stage Fracturing completions (OH-MSF) over tight sandstone gas reservoirs.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"79 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77226584","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}
G. Garcia, H. duMond, V. Mishra, L. Chen, Ron Hayden, C. Babin
A concept platform integrating the precise movement of a linear or azimuthal actuator, such as in instrumented wireline intervention tools (IWIT), with fast pressure measurement is presented. This device is intended to accurately move a measurement probe or sampling assembly either in the longitudinal or azimuthal direction in the wellbore to significantly improve data quality and operational efficiency. Precise movement control enables acquiring data at exact intervals to eliminate errors induced by cable stretching, overpulls, or variable cable creep. Monte Carlo simulations of this concept using current IWIT capabilities suggest significant reduction of the pressure gradient uncertainty over common wireline protocols. The operational procedure includes correlation using standard wireline gamma ray logs, anchoring of the platform at the top of the interval to be tested and performing the distributed survey using a combination of tractors and linear actuators for every probe displacement. Removing cable movement significantly reduces an important source of error in distributed pressure measurements. These acquisition errors induce interpretation uncertainties like position of contacts and connectivity between flow units. These have profound impacts in exploration and appraisal decisions and field development plans. This concept platform would enable reducing the time spent on pressure surveys if similar accuracy to current standard practices is acceptable. Because the remaining source of error is mostly due to gauge accuracy, results show that fewer stations are necessary to replicate standard wireline results. Where accuracy is important, as with distributed pressure measurements to quantify reserves using gradient intersection to define fluid contacts or determine compositional gradients, the proposed approach is shown to significantly reduce gradient error using the same number of stations. We use synthetic data sets built from previous work to show the impact of the error reduction in the position of the fluid contact. IWITs currently used in cased hole employ active anchoring to perform intervention tasks. The controlled downhole force available for these operations goes up to 80,000 lbf while the anchoring force could be up to 150,000 lbf. In the proposed concept platform, this pulling force could be instrumental where there is high risk of differential sticking. By anchoring the upper part of the platform in overlying impermeable intervals, the probe could be lowered into the permeable interval to conduct the pressure survey without exposing the full length of the platform to the pressure differential forces for significant risk mitigation. The high pulling capacity of the anchoring module can be used to apply up/down force on the probe in case of differential sticking without applying high tensions to the wireline cable. The proposed architecture for the concept platform innovatively combines several operational concepts used today
{"title":"Let's Disrupt the Wireline Pressure Testing Practices, Shall We?","authors":"G. Garcia, H. duMond, V. Mishra, L. Chen, Ron Hayden, C. Babin","doi":"10.2118/195016-MS","DOIUrl":"https://doi.org/10.2118/195016-MS","url":null,"abstract":"\u0000 A concept platform integrating the precise movement of a linear or azimuthal actuator, such as in instrumented wireline intervention tools (IWIT), with fast pressure measurement is presented. This device is intended to accurately move a measurement probe or sampling assembly either in the longitudinal or azimuthal direction in the wellbore to significantly improve data quality and operational efficiency.\u0000 Precise movement control enables acquiring data at exact intervals to eliminate errors induced by cable stretching, overpulls, or variable cable creep. Monte Carlo simulations of this concept using current IWIT capabilities suggest significant reduction of the pressure gradient uncertainty over common wireline protocols. The operational procedure includes correlation using standard wireline gamma ray logs, anchoring of the platform at the top of the interval to be tested and performing the distributed survey using a combination of tractors and linear actuators for every probe displacement. Removing cable movement significantly reduces an important source of error in distributed pressure measurements. These acquisition errors induce interpretation uncertainties like position of contacts and connectivity between flow units. These have profound impacts in exploration and appraisal decisions and field development plans.\u0000 This concept platform would enable reducing the time spent on pressure surveys if similar accuracy to current standard practices is acceptable. Because the remaining source of error is mostly due to gauge accuracy, results show that fewer stations are necessary to replicate standard wireline results. Where accuracy is important, as with distributed pressure measurements to quantify reserves using gradient intersection to define fluid contacts or determine compositional gradients, the proposed approach is shown to significantly reduce gradient error using the same number of stations. We use synthetic data sets built from previous work to show the impact of the error reduction in the position of the fluid contact.\u0000 IWITs currently used in cased hole employ active anchoring to perform intervention tasks. The controlled downhole force available for these operations goes up to 80,000 lbf while the anchoring force could be up to 150,000 lbf. In the proposed concept platform, this pulling force could be instrumental where there is high risk of differential sticking. By anchoring the upper part of the platform in overlying impermeable intervals, the probe could be lowered into the permeable interval to conduct the pressure survey without exposing the full length of the platform to the pressure differential forces for significant risk mitigation. The high pulling capacity of the anchoring module can be used to apply up/down force on the probe in case of differential sticking without applying high tensions to the wireline cable.\u0000 The proposed architecture for the concept platform innovatively combines several operational concepts used today","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79856444","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}
G. Craddock, Federico Ríos, Thomas Earl Burky, J. Rodgers, M. Serra, T. Khairy
Side-mounted gun strings present a unique challenge for predictive perforation modeling tools because of their asymmetric geometry. To fully capture the dynamic response of the side-mounted system and more accurately predict the response of any gun system in general, it is important to fully capture the three-dimensional (3D) effects of model geometry and detonation-induced loading. This work details the modeling approach developed for a side-mounted gun system that enables the full geometry to be simulated so that accurate predictions of stresses and displacements could be made; these predictions are necessary for evaluating the damage potential to sensitive tools in the string, It is important to allow operation designers to optimize gun spacing and provide string flexibility to help ensure it can withstand downhole conditions without affecting performance. The simulation methodology was calibrated against previous test measurements, where loads and accelerations were captured during surface testing of a gun string. A detailed model was developed for the planned operation, and simulations were performed to predict the dynamic response of the wellbore fluid and tool string. Multiple damage sensitivities were identified for particular tools, and model results were extracted to evaluate 1) pressure dynamic loading on the tool, 2) displacement levels where movement is expected, and 3) dynamic loading of the tool. These results were provided to the developers of the sensitive tool to help assess potential damage risks. For each case, predictions were compared to previous test results and operation experience to develop a risk evaluation for the planned operation. Further, results were used to make adjustments to the operation to help optimize performance; comparison plots are presented for the different configurations evaluated. This overall process provided confidence to the operators that the operation would be performed successfully with no damage to the sensitive tool.
{"title":"Dynamic Response of Side-Mounted Guns and Assessment of the Potential Damage Risk to Sensitive Tools","authors":"G. Craddock, Federico Ríos, Thomas Earl Burky, J. Rodgers, M. Serra, T. Khairy","doi":"10.2118/195006-MS","DOIUrl":"https://doi.org/10.2118/195006-MS","url":null,"abstract":"\u0000 Side-mounted gun strings present a unique challenge for predictive perforation modeling tools because of their asymmetric geometry. To fully capture the dynamic response of the side-mounted system and more accurately predict the response of any gun system in general, it is important to fully capture the three-dimensional (3D) effects of model geometry and detonation-induced loading.\u0000 This work details the modeling approach developed for a side-mounted gun system that enables the full geometry to be simulated so that accurate predictions of stresses and displacements could be made; these predictions are necessary for evaluating the damage potential to sensitive tools in the string, It is important to allow operation designers to optimize gun spacing and provide string flexibility to help ensure it can withstand downhole conditions without affecting performance.\u0000 The simulation methodology was calibrated against previous test measurements, where loads and accelerations were captured during surface testing of a gun string. A detailed model was developed for the planned operation, and simulations were performed to predict the dynamic response of the wellbore fluid and tool string. Multiple damage sensitivities were identified for particular tools, and model results were extracted to evaluate 1) pressure dynamic loading on the tool, 2) displacement levels where movement is expected, and 3) dynamic loading of the tool. These results were provided to the developers of the sensitive tool to help assess potential damage risks.\u0000 For each case, predictions were compared to previous test results and operation experience to develop a risk evaluation for the planned operation. Further, results were used to make adjustments to the operation to help optimize performance; comparison plots are presented for the different configurations evaluated. This overall process provided confidence to the operators that the operation would be performed successfully with no damage to the sensitive tool.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82720495","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}
Among the many goals of environmental management in Saudi Aramco, protection of special environmental areas is recognized as high priority to both the company and the Kingdom of Saudi Arabia. In line with this objective, Safaniya Onshore Producing Department (SONPD) designated Safaniya area sea water lagoon as Corporate Stewardship Biodiversity Area. The area is estimated to be 6 km2 peninsula, which is located in the north east of the Safaniya Producing Plant, where undisturbed native flora combines with a pristine shallow sea water lagoon, and provide a safe place for land wildlife (foxes, rodents, reptiles), marine wildlife (turtles, shrimps, fish, mollusks) and birds (flamingos, seagulls, etc.). Establishment of the Safaniya Lagoon started with surveying Safaniya and Tanajib Area, in collaboration with Saudi Aramco Environmental Protection Department (EPD) to select the most suitable region for biodiversity development. An establishment procedure was followed to secure the area with fences to limit the accessibility and prevent improper usage. A signboard was installed to identify the area as a sanctuary, forbidding entrance or any type of land use. Site development included mangrove plantation, already existing trash clean-up, and observation any type of waste dumped in the area, to ensure no contamination or danger to the habitat in the lagoon. The department successfully cooperated with Saudi Aramco EPD to plant more than 9,000 mangrove seedlings at the first two years of development. SONPD in collaboration with Society of Advocates and Volunteers for the Environment (S.A.V.E) invited employees with their respected family members to participate in a biodiversity beach clean-up campaign. The campaign helped collect more than 300 kg of waste, consisting of plastic bottles, old ropes, wood, and other waste materials. SONPD, along with its partners and programs, has now established the Safaniya Lagoon ecological and biological diversity sanctuary as a permanent refuge, with in-place protection and future mangrove planting events planned, the area is expected to expand in biodiversity with native flora and fauna, and expand a natural breeding and hatchery. During the winter season, migratory birds — such as flamingos and Amur Falcons, with flyways that pass over Safaniya Lagoon — are seeking warm weather and abundant food supplies. Creation of biodiversity is just the beginning of further area development. The next phase of sanctuary enhancement will be reutilization of tertiary treated wastewater for trees, which will form a wind barrier for mangroves.
{"title":"Safaniya Lagoon Corporate Stewardship Biodiversity Sanctuary","authors":"Moayad Jumaan, Ali Alsinan","doi":"10.2118/194806-MS","DOIUrl":"https://doi.org/10.2118/194806-MS","url":null,"abstract":"\u0000 Among the many goals of environmental management in Saudi Aramco, protection of special environmental areas is recognized as high priority to both the company and the Kingdom of Saudi Arabia. In line with this objective, Safaniya Onshore Producing Department (SONPD) designated Safaniya area sea water lagoon as Corporate Stewardship Biodiversity Area. The area is estimated to be 6 km2 peninsula, which is located in the north east of the Safaniya Producing Plant, where undisturbed native flora combines with a pristine shallow sea water lagoon, and provide a safe place for land wildlife (foxes, rodents, reptiles), marine wildlife (turtles, shrimps, fish, mollusks) and birds (flamingos, seagulls, etc.). Establishment of the Safaniya Lagoon started with surveying Safaniya and Tanajib Area, in collaboration with Saudi Aramco Environmental Protection Department (EPD) to select the most suitable region for biodiversity development. An establishment procedure was followed to secure the area with fences to limit the accessibility and prevent improper usage. A signboard was installed to identify the area as a sanctuary, forbidding entrance or any type of land use. Site development included mangrove plantation, already existing trash clean-up, and observation any type of waste dumped in the area, to ensure no contamination or danger to the habitat in the lagoon. The department successfully cooperated with Saudi Aramco EPD to plant more than 9,000 mangrove seedlings at the first two years of development. SONPD in collaboration with Society of Advocates and Volunteers for the Environment (S.A.V.E) invited employees with their respected family members to participate in a biodiversity beach clean-up campaign. The campaign helped collect more than 300 kg of waste, consisting of plastic bottles, old ropes, wood, and other waste materials. SONPD, along with its partners and programs, has now established the Safaniya Lagoon ecological and biological diversity sanctuary as a permanent refuge, with in-place protection and future mangrove planting events planned, the area is expected to expand in biodiversity with native flora and fauna, and expand a natural breeding and hatchery. During the winter season, migratory birds — such as flamingos and Amur Falcons, with flyways that pass over Safaniya Lagoon — are seeking warm weather and abundant food supplies. Creation of biodiversity is just the beginning of further area development. The next phase of sanctuary enhancement will be reutilization of tertiary treated wastewater for trees, which will form a wind barrier for mangroves.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88848973","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}
T. Bérard, A. Gisolf, J. Desroches, Hemant Gurav, N. Chugunov, R. Prioul
We applied a recently introduced method to complete a feasibility assessment and design a stress testing campaign in a deep-water field in West Africa. We first reviewed the previous—and unsuccessful—campaign. Test data were inverted together with a priori knowledge from an independent geomechanical study to develop an understanding of the ambient conditions. Based on this understanding, the current campaign's chance of success (COS) was estimated to be 10%, with 1,000 psi of pressure capacity lacking to reach 95%. By analyzing the sensitivity of the risk to formation properties and design parameters, we identified various options to prevent this high, yet seemingly controllable, risk of test failure. Among them, a 1.7-ppg increase of mud density, expected to increase the COS to 80%, was deemed most effective and implemented. With 4 successful tests out of 10, the second campaign was more successful than the previous one. Yet this success rate was lower than anticipated. We inverted the second campaign's test data to revise our understanding of the in situ conditions. Our main findings are that, for this particular case, (i) the magnitude of the minimum horizontal stress was significantly higher than initially thought, (ii) the minimum horizontal stress and the horizontal stress ratio appeared to be anticorrelated, and (iii) the COS was extremely sensitive to the minimum horizontal stress. The conditions solved using the second campaign's dataset also explained the first campaign's negative outcome. This case study demonstrates that (i) the proposed planning method enables return of experience to be captured and leveraged from one test, or one series of tests, to the next, and the design of formation stress tests to be optimized, leading to an improved success rate of formation stress tests; and (ii) the proposed inversion scheme allows insight to be gained from both successful and unsuccessful tests, including in formation conditions other than the minimum horizontal stress.
{"title":"Quantitative Risk Management Improves the Success Rate of Micro-Hydraulic Fracturing Stress Tests","authors":"T. Bérard, A. Gisolf, J. Desroches, Hemant Gurav, N. Chugunov, R. Prioul","doi":"10.2118/195008-MS","DOIUrl":"https://doi.org/10.2118/195008-MS","url":null,"abstract":"\u0000 We applied a recently introduced method to complete a feasibility assessment and design a stress testing campaign in a deep-water field in West Africa. We first reviewed the previous—and unsuccessful—campaign. Test data were inverted together with a priori knowledge from an independent geomechanical study to develop an understanding of the ambient conditions. Based on this understanding, the current campaign's chance of success (COS) was estimated to be 10%, with 1,000 psi of pressure capacity lacking to reach 95%. By analyzing the sensitivity of the risk to formation properties and design parameters, we identified various options to prevent this high, yet seemingly controllable, risk of test failure. Among them, a 1.7-ppg increase of mud density, expected to increase the COS to 80%, was deemed most effective and implemented. With 4 successful tests out of 10, the second campaign was more successful than the previous one. Yet this success rate was lower than anticipated. We inverted the second campaign's test data to revise our understanding of the in situ conditions. Our main findings are that, for this particular case, (i) the magnitude of the minimum horizontal stress was significantly higher than initially thought, (ii) the minimum horizontal stress and the horizontal stress ratio appeared to be anticorrelated, and (iii) the COS was extremely sensitive to the minimum horizontal stress. The conditions solved using the second campaign's dataset also explained the first campaign's negative outcome.\u0000 This case study demonstrates that (i) the proposed planning method enables return of experience to be captured and leveraged from one test, or one series of tests, to the next, and the design of formation stress tests to be optimized, leading to an improved success rate of formation stress tests; and (ii) the proposed inversion scheme allows insight to be gained from both successful and unsuccessful tests, including in formation conditions other than the minimum horizontal stress.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89316894","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}
3D wide azimuth seismic data plays a vital role in fault interpretation, which has significant importance during exploration and development stages. Interpreting faults in 3D seismic data is one of the most time consuming and challenging process especially when dealing with poor quality seismic data. This paper provides a complete workflow and example of its application from seismic pre-conditioning to fault detection and extraction automatically based on published concepts by Dave Hale. With recent advancement in computer technology, multi-threaded algorithms and data driven methodologies, geoscientists can automatically detect and interpret virtually all discontinuities in seismic data in an efficient manner. This workflow involves random and coherent noise suppression, seismic likelihood attributes generation to enhance the discontinuities, detect faults and extract them from thinned fault likelihood volume. Unlike other fault tracking methods that use local seismic continuity attributes, such as coherency, this automated method incorporates aspects of Hale's fault-oriented semblance algorithm, which highlights fault planes with unprecedented clarity. This methodology has been successfully applied on complex faulted reservoirs. It contributes to the extraction of detailed discontinuity information (minor and major) from 3D seismic data. The traditional manual interpretation step that follows the detection of faults was time consuming and error prone. Automated fault interpretation improves the fault tracking accuracy, consistency and significantly reduces fault interpretation time in prospect generation. This workflow will optimize and reduce uncertainty associated with the seismic fault interpretation process.
{"title":"The Impact of Automated Fault Detection and Extraction Technology on Seismic Interpretation","authors":"A. Al-Maskeen, Sadaqat S. Ali, Muhammad Khan","doi":"10.2118/194819-MS","DOIUrl":"https://doi.org/10.2118/194819-MS","url":null,"abstract":"\u0000 3D wide azimuth seismic data plays a vital role in fault interpretation, which has significant importance during exploration and development stages. Interpreting faults in 3D seismic data is one of the most time consuming and challenging process especially when dealing with poor quality seismic data. This paper provides a complete workflow and example of its application from seismic pre-conditioning to fault detection and extraction automatically based on published concepts by Dave Hale. With recent advancement in computer technology, multi-threaded algorithms and data driven methodologies, geoscientists can automatically detect and interpret virtually all discontinuities in seismic data in an efficient manner.\u0000 This workflow involves random and coherent noise suppression, seismic likelihood attributes generation to enhance the discontinuities, detect faults and extract them from thinned fault likelihood volume. Unlike other fault tracking methods that use local seismic continuity attributes, such as coherency, this automated method incorporates aspects of Hale's fault-oriented semblance algorithm, which highlights fault planes with unprecedented clarity.\u0000 This methodology has been successfully applied on complex faulted reservoirs. It contributes to the extraction of detailed discontinuity information (minor and major) from 3D seismic data. The traditional manual interpretation step that follows the detection of faults was time consuming and error prone. Automated fault interpretation improves the fault tracking accuracy, consistency and significantly reduces fault interpretation time in prospect generation. This workflow will optimize and reduce uncertainty associated with the seismic fault interpretation process.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87131651","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 Cambro-Ordovician succession of Saudi Arabia comprises dominantly siliciclastic sediments deposited in a passive margin intracratonic setting and includes the fluvial to marginal marine Saq Formation (Late Cambrian to early Middle Ordovician), the marine Qasim Formation (late Middle to Late Ordovician) and the glaciogenic Sarah Formation (Hirnantian, latest Ordovician). The Saq Formation is subdivided into the Risha Member (Late Cambrian) and the Sajir Member (Early to Middle Ordovician). Palynological age-control in the Risha Member is provided by a characteristic acritarch assemblage (CB1 Palynozone) which contains well-known Furongian (Late Cambrian) diagnostic taxa (e.g., Trunculumarium revinium, Timofeevia phosphoritica and Ninadiacrodium dumontii), as recorded in one subsurface locality in the Arabian Gulf. This typical assemblage occurs worldwide in Furongian-aged strata and not only permits a confident age- attribution, but also indicates an open marine facies within the predominantly fluvial to marginal marine lower Saq Formation. In Oman, the same assemblage occurs in the Al-Bashair Member of the Andam Formation. In the lower part of the Sajir Member, one acritarch assemblage characterized by the presence of Acanthodicaodium angustum and Vulcanisphaera spp., was described from a subsurface section in Eastern Saudi Arabia, indicating an earliest Ordovician (Tremadocian) age. This assemblage forms the O6 Palynozone and suggests correlation with the Mabrouk Member of the Andam Formation in Oman. The top of the Sajir Member of the Saq Formation is characterized by mud-rich bioturbated deposits which typically yield a distinct palynological assemblage (O5 Palynozone), characterized by dominance of morphologically distinctive sporomorphs (e.g., Virgatasporites spp., various hilate sporomorphs) and characteristic acritarch species such as ?Clypeolus sp., ?Cymatiosphaera sp., ?Retialetes sp., and Barakella spp. The assemblage is also characterized by the first occurrence of some typical Middle Ordovician acritarch taxa such as Arkonia, Striatotheca, and Frankea. Among the chitinozoan, Siphonochitina formosa is typically represented. The age of this assemblage spans the Dapingian to earliest Darriwilian, in agreement with faunal evidence. The assemblage indicates a marginal marine, restricted paleoenvironment. Virtually identical palynological assemblages occur in Oman in the Saih-Nihayda Formation, considered of late Dapingian to Darriwilian age. More specifically, it is suggested here that the O5 Palynozone of Saudi Arabia permits correlation of the upper Sajir Member of the Saq Formation with the lower, sand-prone, part of the Saih Nihayda Formation in Oman.
{"title":"Palynological Correlation of the Late Cambrian to Middle Ordovician Saq Formation in Saudi Arabia and Equivalent Strata in Oman Manuscript Title","authors":"M. Vecoli, C. Cesari","doi":"10.2118/195108-MS","DOIUrl":"https://doi.org/10.2118/195108-MS","url":null,"abstract":"\u0000 The Cambro-Ordovician succession of Saudi Arabia comprises dominantly siliciclastic sediments deposited in a passive margin intracratonic setting and includes the fluvial to marginal marine Saq Formation (Late Cambrian to early Middle Ordovician), the marine Qasim Formation (late Middle to Late Ordovician) and the glaciogenic Sarah Formation (Hirnantian, latest Ordovician).\u0000 The Saq Formation is subdivided into the Risha Member (Late Cambrian) and the Sajir Member (Early to Middle Ordovician). Palynological age-control in the Risha Member is provided by a characteristic acritarch assemblage (CB1 Palynozone) which contains well-known Furongian (Late Cambrian) diagnostic taxa (e.g., Trunculumarium revinium, Timofeevia phosphoritica and Ninadiacrodium dumontii), as recorded in one subsurface locality in the Arabian Gulf. This typical assemblage occurs worldwide in Furongian-aged strata and not only permits a confident age- attribution, but also indicates an open marine facies within the predominantly fluvial to marginal marine lower Saq Formation. In Oman, the same assemblage occurs in the Al-Bashair Member of the Andam Formation. In the lower part of the Sajir Member, one acritarch assemblage characterized by the presence of Acanthodicaodium angustum and Vulcanisphaera spp., was described from a subsurface section in Eastern Saudi Arabia, indicating an earliest Ordovician (Tremadocian) age. This assemblage forms the O6 Palynozone and suggests correlation with the Mabrouk Member of the Andam Formation in Oman.\u0000 The top of the Sajir Member of the Saq Formation is characterized by mud-rich bioturbated deposits which typically yield a distinct palynological assemblage (O5 Palynozone), characterized by dominance of morphologically distinctive sporomorphs (e.g., Virgatasporites spp., various hilate sporomorphs) and characteristic acritarch species such as ?Clypeolus sp., ?Cymatiosphaera sp., ?Retialetes sp., and Barakella spp. The assemblage is also characterized by the first occurrence of some typical Middle Ordovician acritarch taxa such as Arkonia, Striatotheca, and Frankea. Among the chitinozoan, Siphonochitina formosa is typically represented. The age of this assemblage spans the Dapingian to earliest Darriwilian, in agreement with faunal evidence. The assemblage indicates a marginal marine, restricted paleoenvironment. Virtually identical palynological assemblages occur in Oman in the Saih-Nihayda Formation, considered of late Dapingian to Darriwilian age. More specifically, it is suggested here that the O5 Palynozone of Saudi Arabia permits correlation of the upper Sajir Member of the Saq Formation with the lower, sand-prone, part of the Saih Nihayda Formation in Oman.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"409 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90404708","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}
Polymer gel treatment is a successful technology for conformance improvement. Achieving effective deep conformance control in high-temperature reservoirs requires improving the performance of gel in these environments and a deep understanding of gel-conformance control mechanisms inside reservoir rocks. In this work, a laboratory study was conducted to evaluate a polyacrylamide/chromium gel system for a carbonate reservoir at high-temperature and high-salinity (HTHS) conditions. Displacement experiments combined with nuclear magnetic resonance (NMR) measurements were performed to investigate the mechanisms of conformance treatment as well as demonstrate the potential of oil production improvement by a gelling system. Coreflooding tests were performed on carbonate core samples with different configurations of high-permeability channels. Both gel treatment and polymer flooding experiments were conducted to quantify and differentiate between fluid-diversion and viscous effects on oil production improvement due to the treatment. Detailed spatial fluid variations inside the core samples before and after gel treatment were closely monitored using low-field NMR techniques. Both coreflooding experiments and NMR measurements clearly showed that significant oil production improvement was achieved by gel treatment. The bypassed oil during waterflooding was effectively mobilized. Gel treatment is more efficient in oil production improvement for more heterogeneous core samples. The comparison study of gel treatment and polymer flooding helps gain insight into the mechanisms of oil displacement. Results show that the blockage or fluid-diversion effect plays a more significant role in oil production improvement after gel treatment. The viscous effect of gelant flow helps mobilize oil in the matrix region. The oil production improvement by gel treatment is mainly attributed to the fluid-diversion effect, especially for the treatment in high-permeable configuration. Moreover, results of the study demonstrate the potential of the studied gel system for carbonate reservoirs at high temperature. NMR techniques add additional valuable information to conventional displacement tests to identify the dominant mechanisms of oil mobilization.
{"title":"A Closer Look on Viscosity and Divergence Effects of Gel Treatments in Fractured Systems","authors":"A. Alshehri, Jinxun Wang, H. Kwak, A. Alsofi","doi":"10.2118/194964-MS","DOIUrl":"https://doi.org/10.2118/194964-MS","url":null,"abstract":"\u0000 Polymer gel treatment is a successful technology for conformance improvement. Achieving effective deep conformance control in high-temperature reservoirs requires improving the performance of gel in these environments and a deep understanding of gel-conformance control mechanisms inside reservoir rocks.\u0000 In this work, a laboratory study was conducted to evaluate a polyacrylamide/chromium gel system for a carbonate reservoir at high-temperature and high-salinity (HTHS) conditions. Displacement experiments combined with nuclear magnetic resonance (NMR) measurements were performed to investigate the mechanisms of conformance treatment as well as demonstrate the potential of oil production improvement by a gelling system. Coreflooding tests were performed on carbonate core samples with different configurations of high-permeability channels. Both gel treatment and polymer flooding experiments were conducted to quantify and differentiate between fluid-diversion and viscous effects on oil production improvement due to the treatment. Detailed spatial fluid variations inside the core samples before and after gel treatment were closely monitored using low-field NMR techniques.\u0000 Both coreflooding experiments and NMR measurements clearly showed that significant oil production improvement was achieved by gel treatment. The bypassed oil during waterflooding was effectively mobilized. Gel treatment is more efficient in oil production improvement for more heterogeneous core samples. The comparison study of gel treatment and polymer flooding helps gain insight into the mechanisms of oil displacement.\u0000 Results show that the blockage or fluid-diversion effect plays a more significant role in oil production improvement after gel treatment. The viscous effect of gelant flow helps mobilize oil in the matrix region. The oil production improvement by gel treatment is mainly attributed to the fluid-diversion effect, especially for the treatment in high-permeable configuration. Moreover, results of the study demonstrate the potential of the studied gel system for carbonate reservoirs at high temperature. NMR techniques add additional valuable information to conventional displacement tests to identify the dominant mechanisms of oil mobilization.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82698447","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}
Global energy demand has driven the petroleum industry to develop hydrocarbon resources from extremely harsh formations which contain ultra-high pressure and temperature (HPHT) reservoirs. Ultra-high density drilling fluids are critical to successful drilling and completion practices in all of these wells. In this paper, potential weighting materials were systematically evaluated and screened to accomplish an ultra-high density oil-based drilling fluid system (19.62 to 22.12lb/gal) aimed to utilize in ultra HPHT conditions (>30000psi and >410°F). Several potential high-density weighting materials were evaluated in the laboratory conditions. Basic properties (pure density, particle size/distribution, surface area etc.) were evaluated and compared. Special treatments were conducted to optimize the properties of weighting materials. HPHT filtration tests under static and dynamic conditions were conducted at higher than 410°F and 300 psi. Real cores with an average porosity of 19% and an average permeability of 50 mD were used in the filtration tests. Rheological properties, sag tendency, the volume of filtrate, and the filtrate cake characterization of oil-based drilling fluids were measured before and after heating at 410°F for 16 hours. Results revealed that ultra-micro manganese and ilmenite complex after suitable surface treatment could act as an ideal weighting material than ultra-pure barite or other materials, which could fail in rheology and sag controlling measurement with such high temperature and density. The viscosity and filtration analysis confirmed the stability and reliability of this novel ultra-high density oil-based drilling fluid. This study developed a challenged drilling fluid system under critical testing states, as well as established a systematical laboratory evaluation and screening procedure of weighting materials for ultra-deep wells and contributed recommendations on how to utilize it in the fields.
{"title":"Laboratory Evaluation of Weighting Materials for Ultra-High Density Oil-Based Drilling Fluids in Ultra-HPHT Wellbore Applications","authors":"Qinghui Li, Jinzhi Zhu, Shaoxuan Li, Zhang Shaojun, Nasr-El-Din Hisham, Ren Lingling, Jiaxue Li, M. Al-Mujalhem","doi":"10.2118/194842-MS","DOIUrl":"https://doi.org/10.2118/194842-MS","url":null,"abstract":"\u0000 Global energy demand has driven the petroleum industry to develop hydrocarbon resources from extremely harsh formations which contain ultra-high pressure and temperature (HPHT) reservoirs. Ultra-high density drilling fluids are critical to successful drilling and completion practices in all of these wells. In this paper, potential weighting materials were systematically evaluated and screened to accomplish an ultra-high density oil-based drilling fluid system (19.62 to 22.12lb/gal) aimed to utilize in ultra HPHT conditions (>30000psi and >410°F).\u0000 Several potential high-density weighting materials were evaluated in the laboratory conditions. Basic properties (pure density, particle size/distribution, surface area etc.) were evaluated and compared. Special treatments were conducted to optimize the properties of weighting materials. HPHT filtration tests under static and dynamic conditions were conducted at higher than 410°F and 300 psi. Real cores with an average porosity of 19% and an average permeability of 50 mD were used in the filtration tests. Rheological properties, sag tendency, the volume of filtrate, and the filtrate cake characterization of oil-based drilling fluids were measured before and after heating at 410°F for 16 hours.\u0000 Results revealed that ultra-micro manganese and ilmenite complex after suitable surface treatment could act as an ideal weighting material than ultra-pure barite or other materials, which could fail in rheology and sag controlling measurement with such high temperature and density. The viscosity and filtration analysis confirmed the stability and reliability of this novel ultra-high density oil-based drilling fluid.\u0000 This study developed a challenged drilling fluid system under critical testing states, as well as established a systematical laboratory evaluation and screening procedure of weighting materials for ultra-deep wells and contributed recommendations on how to utilize it in the fields.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79570736","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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