Day 2 Wed, October 13, 2021最新文献

{"title":"A Practical Approach to Manage Top-Hole Collision Risk in Crowded Fixed Platform: Implementation in Offshore East Kalimantan","authors":"A. H. Feizal, Made Allan Pribadi, Eka Pambudi Riambomo, Ridwan Durachman","doi":"10.2118/205533-ms","DOIUrl":"https://doi.org/10.2118/205533-ms","url":null,"abstract":"\u0000 The requirement of drilling in very close proximity to adjacent wells in surface hole section has been common as field become more crowded. This is true especially in offshore mature field where the last wells are drilled on a dense platform. In Santan Field, East Kalimantan, conductor pipes were driven between the existing wells since sidetrack or platform extension options were not available at the time while there are still opportunity for infill and step out wells.\u0000 This situation introduces challenges on well construction in term of collision avoidance since the spacing between the wells are tight from surface point. The distance between slots is as low 1 meter from center-to-center, and 0.64 meter between wall-to-wall. Directional works was also required at shallow depth to kick of the well as per trajectory requirement.\u0000 The risk of unplanned intersections with adjacent well can lead to financial loss, personnel safety as well as environmental issue. A comprehensive risk assessment were conducted during the planning phase as the safety of drilling operation has been one of the main concerns. Mitigations plan were then formulated with the objectives to manage the negative consequences to acceptable level.\u0000 During the planning phase, detail anti-collision procedure was executed to evaluate the collision risk. On the field, several activities were carried out on adjacent wells prior to rig move in as mitigations measure: 1) Rig less resurvey, 2) Well integrity inspection, and 3) Well barrier placement. While drilling, following strategies were performed: 1) GWD utilization, 2) Monitoring on subject and adjacent wells, and 3) Collision-tolerant drilling bit application\u0000 The all-surface hole were drilled safely without any HSE or reliability issue. No major indications of well collision were observed. However, the drilling time took bit longer than usual performance due to drilling controlled manner for anti-collision precautions.\u0000 This paper explain how well collision mitigations was implemented in Santan Field, East Kalimantan, which can be a reference for further drilling as a successful case of top-hole drilling on a dense fixed platform. The method is expected to gain economic value, which is notably beneficial in mature field.","PeriodicalId":11017,"journal":{"name":"Day 2 Wed, October 13, 2021","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74632797","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}

{"title":"Extending Gravel Pack Carrier Fluid Performance in Highly Deviated Well for 7-Inch Gravel Pack Completion without Shunt Tube by Using High Grade Suspension Gravel Pack Fluid in Mahakam Offshore","authors":"Putu Yudis, Doffie Cahyanto Santoso, Edo Tanujaya, Kristoforus Widyas Tokoh, R. Sinaga, Tomi Sugiarto, M. Maharanoe","doi":"10.2118/205592-ms","DOIUrl":"https://doi.org/10.2118/205592-ms","url":null,"abstract":"\u0000 In unconsolidated sand reservoirs, proper sand control completion methods are necessary to help prevent reservoir sand production. Failure due to sand production from surface equipment damage to downhole equipment failures which can ultimately result in loss of well integrity and worst-case catastrophic failure. Gravel Packing is currently the most widely used sand control method for controlling sand production in the oil and gas industry to deliver a proppant filter in the annular space between an unconsolidated formation and a centralized integrated screen in front of target zones. Additional mechanical skin and proper proppant packing downhole are the most critical objective when implementing gravel packs as part of a completion operation.\u0000 This paper presents a case history of Well SX that was designed as single-trip multi-zone completion 7-inch casing, S-shape well type, having 86 deg inclination along 1300 meters, 4 to 5-meter perforation range interval and 54 deg inclination in front of the reservoir with total depth of 3800 mMD. The well consists of 4 zones of interest which had previously been treated with a two-trip gravel pack system. While Well NX was designed as single-trip multi-zone completion in 7-inch casing, J-shape well type, 8-meter perforation interval and 84 deg inclination in front of the reservoir with total depth of 3300 mMD. The well consists of two zones of interest which had previously been treated with a single-trip gravel pack system. Both wells are in the Sisi-Nubi field offshore Mahakam on East Kalimantan Province of Borneo, Indonesia. This paper discusses the downhole completion design and operation as well as the changes to the gravel pack carrier which overcame challenges such as high friction in the 7\" lower completion and the potential for an improper annular gravel pack due to the lack of shunt tubes in a highly deviated wellbore. In vertical wellbores, obtaining a complete annular pack is relatively easy to accomplish but in highly deviated wellbores, the annular gravel pack is more difficult to achieve and can contribute additional skin. Tibbles at al (2007) noted that installing a conventional gravel pack could result in skin values of 40 to 50, mostly due to poor proppant packing in perforation tunnels.\u0000 Therefore, operator required to find a reliable gravel pack carrier fluid optimization for typical highly deviated wells to overcome the potential sand production issues by applying a single-trip multi-zone sand control system across both zones (without shunt tubes) along with the utilization of a high-grade xanthan biopolymer gravel pack carrier fluid.\u0000 Laboratory testing was conducted to ensure that the gravel pack fluid could transport the sand to the sand control completion, large enough to allow for a complete annular pack and still allow the excess slurry to be circulated out of the hole. Electronic gravel pack simulations were performed to ensure that rate/pressure/sand concentration would allow ","PeriodicalId":11017,"journal":{"name":"Day 2 Wed, October 13, 2021","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76625321","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}

{"title":"Artificial Intelligence Method of Flow Unit Division Based on Waveform Clustering: A Case Study on Zhetybay Oil Field, South Mangyshalk Basin, Kazakhstan","authors":"Li-bing Fu, Jun Ni, Yuming Liu, Xuanran Li, Anzhu Xu","doi":"10.2118/205740-ms","DOIUrl":"https://doi.org/10.2118/205740-ms","url":null,"abstract":"\u0000 The Zhetybay Field is located in the South Mangyshlak Sub-basin, a delta front sedimentary reservoir onshore western Kazakhstan. It was discovered in 1961 and first produced by waterflooding in 1967. After more than 50 years of waterflooding development, the reservoirs are generally in the mid-to-high waterflooded stage and oil-water distribution becomes complicated and chaotic. It is very difficult to handle and identify so much logging data by hand since the oilfield has the characteristics of high-density well pattern and contains rich logging information with more than 2000 wells. The wave clustering method is used to divide the sedimentary rhythm of the logging curve. Sedimentary microfacies manifested as a regression sequence, with four types of composite sand bodies including the composite estuary bar and distributary channel combination, the estuary bar connected to the dam edge and the distributing channel combination, the isolated estuary bar and distributing channel combination, and the isolated beach sand. In order to distinguish the flow units, the artificial intelligence algorithm-support vector machine (SVM) method is established by learning the non-linear relationship between flow unit categories and parameters based on developing flow index and reservoir quality factor, summarizing permeability logarithm and porosity degree parameters in the sedimentary facies, and analyzing the production dynamic. The flow units in Zhetybay oilfield were classified into 4 types: A, B1, B2 and B3, and the latter three are the main types. Type A is distributed in the river, type B1 is distributed in the main body of the dam, type B2 is mainly distributed in the main body of the dam, and some of B2 is distributed in the dam edge, and B3 is located in the dam edge, sheet sand and beach sand. The results show that the accuracy of flow unit division by support vector machines reaches 91.1%, which clarifies the distribution law of flow units for oilfield development. This study is one of the significant keys for locating new wells and optimizing the workovers to increase recoverable reserves. It provides an effective guidance for efficient waterflooding in this oilfield.","PeriodicalId":11017,"journal":{"name":"Day 2 Wed, October 13, 2021","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84844978","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}

{"title":"First Success of Marine Shale Gas in Ordos Basin: A Review of Recent Exploration Breakthrough in Ordovician Wulalike Formation","authors":"Suotang Fu, Sheng-li Xi, Jian Yu, Xifeng Hu, Yuan Liu, J. Zhang, Liang Cai, Shenzhuan Li, Xianran Zhao, Jinlong Wu, Hongzhi Guo","doi":"10.2118/205637-ms","DOIUrl":"https://doi.org/10.2118/205637-ms","url":null,"abstract":"\u0000 Ordos basin in central China is well known for its rich accumulation of natural resources, including Triassic tight oil and Permian tight gas. A recent exploration breakthrough shows that Ordovician shale in the same basin is also promising. The purpose of this study is to capture the engineering details of two horizontal exploration wells exploration in Wulalike formation, which mark the first production of marine shale gas in Ordos basin.\u0000 The Ordovician Wulalike formation in the Ordos basin was previously seen as source rock. During early exploration in the 2010s, the formation was found to be gas bearing. However, the Wulalike shale formation shows very different features compared to the Triassic lacustrine shale in the same basin and the Silurian marine shale from Sichuan. The abundance of natural fissures, the low reservoir pressure, and the tendency to produce water are unique challenges and concerns for the Wulalike shale formation.\u0000 Based on the pilot well evaluations, two horizontal wells were drilled and completed in the Wulalike formation in different locations in the western Ordos basin in 2019–2020. Both wells were well-landed in the target zone and were completed with multistage large-scale fracturing treatments. Following the well completions, flowback and production tests lasted for 3 to 5 months. Production tests showed that well 1 reached an economically acceptable gas rate in natural flow for a long-term period, producing 20,000 to 60,000 std m3/d, and well 2 produced good gas in the early period but was soon overwhelmed by massive water production. Both wells were evaluated with production logging tools. In well 1, fiber-optic distributed acoustic sensing (DAS) and distributed temperature sensing (DTS) were used, and in well 2, a production logging tool (PLT) was used.\u0000 The positive gas production from both wells marks the first production of marine shale gas in the Ordos basin. The understanding of the geology and reservoir, the use of unconventional fracturing and completion practices, the assistance of energized fluid, and post-treatment artificial lift are the technologies that helped achieve this success. Further study is needed on the complexity of the natural fissures to lower the risk of unwanted water production from the Wulalike rocks.\u0000 The first successful production from the Wulalike is very critical for the exploration of the Ordovician section in the Ordos basin because it helps to confirm a favorable exploration and appraisal area of 2000 to 3000 km2, which has the potential to turn into a huge reserve. This case study provides value from a technical standpoint, as very few success stories have been reported from low-pressure shale gas previously in China or worldwide.","PeriodicalId":11017,"journal":{"name":"Day 2 Wed, October 13, 2021","volume":"255 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74801188","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}

{"title":"High Density Gravel Packing Fluid for High-Temperature Deep Water Wells","authors":"Mayur Deshpande, Shamit Rathi, S. Songire, Ravikant S. Belakshe, John Davis","doi":"10.2118/205577-ms","DOIUrl":"https://doi.org/10.2118/205577-ms","url":null,"abstract":"\u0000 Southeast offshore India reservoirs have high-temperature deep water wells with significantly high pressures and unconsolidated sandstone formations. Controlling sand production is a major issue from inception to well completion and throughout the life of the well. A high density brine is required due to the high bottom hole pressures, thus executing sand control operations using such a high density brine as the base fluid for the gravel pack carrier fluid combined with the elevated temperatures is a significant challenge. A case is presented where a high-density temperature-resistant gravel packing fluid was optimized for a BHT of 320°F using a high-density brine. Additionally, the pH of the fluid was crucial considering the significant presence of CO2 in the formation, which was anticipated to affect asset integrity due to corrosion at low pH.\u0000 A biopolymer-based fluid with oxidizing breaker was required in 14.2 ppg potassium-cesium formate brine and 12.5 ppg potassium formate brine. The fluid required evaluation for rheology and stability at 320°F, and at a shear rate of 170 s-1 with two conditions of viscosity to be sustained in the range of 75- 150 cP and 150-250 cP for the initial four-hour duration. The same fluid, after four hours, was also required to be broken within fourteen days. The fluid with the optimized formulation in regard with stability and rheology was further required to pass an acceptable sand suspension of ≤ 5% settling. Finally, the optimized fluid was required to show negligible corrosion effects on the downhole metallurgies. The stability and rheology were studied using a HPHT concentric cylinder viscometer. The sand suspension and corrosion characteristics were studied using an HPHT autoclave. The same fluid was studied with an acid breaker as a contingency for wells without CO2-related issues.\u0000 After an extensive study, 12.72 gal/Mgal liquid gel concentrate of biopolymer when hydrated in 14.2 ppg and 15.45 gal/Mgal liquid gel concentrate of biopolymer, when hydrated in 12.5 ppg, providing viscosity in the range of 150-250 cP with 3 gal/Mgal and 5 gal/Mgal oxidizing breaker were selected, respectively.\u0000 The optimized formulations passed sand suspension and had a pH in the range of 8-10, which imparted negligible corrosion loss to chrome- and nickel-based metallurgies. At the same conditions, the fluid showed acceptable results with 20 gal/Mgal organic acid breaker where the pH was ≤ 7.\u0000 The combination of a commonly used biopolymer and a mixed formate brine produced a thermally stable fluid with unconventional chemistry, applicable for high-temperature, high-density conditions. With further study, it is expected that the temperature limit of this fluid can be extended beyond 320°F.\u0000 The formulation for potassium formate brine was also tested at using field scale equipment to check for ease of mixing, reproducibility of results and for determining friction values when pumped at a certain rate via shunts. The fluid was","PeriodicalId":11017,"journal":{"name":"Day 2 Wed, October 13, 2021","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74400787","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}

{"title":"Access to Environmentally Friendly Energy and Capacity Building for Communities in the 3T Frontier, Outermost and Least Developed Region Through the Corporate Social Responsibility Program","authors":"Agung Wibowo, Anton Humala Doloksaribu, Adi Rahman","doi":"10.2118/205598-ms","DOIUrl":"https://doi.org/10.2118/205598-ms","url":null,"abstract":"\u0000 PT. Pertamina EP Asset 5 Tarakan Field (PEP Tarakan Field) is one of the upstream oil and gas companies that play an active role in improving the community's welfare around its operational area through social responsibility programs. Through renewable energy access, community empowerment was one of the activities carried out in Tepian Village, Sembakung District, Nunukan Regency, North Kalimantan Province. This activity aimed to provide an alternative energy source that is environmentally friendly and more cost-effective to help reduce the cost of living for the underprivileged communities in the village.\u0000 The concept of implementing the social responsibility program adapted by Tarakan Field consists of 4 elements: Organizing Identity, Organizing Transactivity, Organizing System, and Organizing Accountability. The program implementation began with a social mapping that includes data on beneficiaries of the diesel generator conversion program into a Solar-cell Home System. Then, conducted a Focus Group Discussion with village officials and related agencies to listen to suggestions and input on this program. Approximately 30 housing units/140 people from the pre-prosperous group became the beneficiaries of this program. Several residents were also given training in maintenance skills of the Solar-cell Home System unit, following the standards and procedures implemented by the company. Periodically, monitoring is also carried out to see how far the beneficiaries feel the program's impact. In addition, the implementation of monitoring was also helpful to detect obstacles encountered in program implementation so that improvements could be made immediately. Evaluation is carried out every year and at the end of the program mentoring period to see how far the beneficiaries feel the program's impact. Monitoring and evaluation carried out by Tarakan Field also involved other agencies such as academics to involve various disciplines.\u0000 After this program was implemented, there was a 50% living costs reduction of the underprivileged groups because they no longer needed to buy diesel to turn on the diesel generator as a source of electrical energy. In addition, there is a reduction in carbon emissions from diesel generators and a decrease in noise levels in the environment around the village.\u0000 This social responsibility program also supported the government's third point in the Nawacita programs: to build Indonesia from the margins and support the program to achieve the seven sustainable development goals (SDGs), namely clean and affordable energy. In 2017, this program became a trigger for the Ministry of Energy and Mineral Resources Republic of Indonesia assistance program in the form of a Solar-cell unit with a capacity of 75 kWp, which can accommodate the needs of the entire house network in Tepian Village.","PeriodicalId":11017,"journal":{"name":"Day 2 Wed, October 13, 2021","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81630369","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}

{"title":"Understanding the Facies Architecture of a Fluvial-Aeolian of Tensleep Formation Using a Machine Learning Approach","authors":"L. Hardanto","doi":"10.2118/205733-ms","DOIUrl":"https://doi.org/10.2118/205733-ms","url":null,"abstract":"\u0000 Many aeolian dune reservoirs are built from various dune types, and many may remain unrecognized in subsurface work. The challenge is to tackle the complex geological architecture of dune types within the Teapot Dome dataset caused by wind and water erosion. Machine Learning (ML) helps predict facies architecture away from boreholes using seismic attributes and facies logs. It provides a detailed understanding of the facies architecture analysis of the relationship between the fluvial–aeolian environment in Tensleep Formation based on seismic and well data. It allows operators to wisely assess their hydrocarbon reservoir, improve safety, and maximize oil and gas production investment.\u0000 The data from the Teapot Dome field (Naval Petroleum Reserve No.3 - NPR-3) provides a good testing ground for Machine Learning, as it is easy to validate and prove its value. This study will show how the ML supervised learning method incorporating Neural Network Seismic Inversion (NNSI) can successfully create porosity log and facies volumes. Moreover, unsupervised learning using Multi-Resolution Graph-based clustering (MRGC) can be used to classify the facies logs. NNSI has 0.963 for the cross-correlation coefficients for all wells. The ML approach was used to help recognize the type of aeolian dune reservoirs in the subsurface and correlate the well log and facies volumes. In addition, ML allowed the distinct sequences and reconstruction of their depositional history in the Tensleep Formation. This study also refers briefly to other examples of fluvial-aeolian facies architecture worldwide. It successfully found the ancient model in an existing modern fluvial-aeolian environment, revealing hidden information about facies architecture based on the geometrical shape of geobodies in the oil-producing reservoir in the Tensleep Formation.","PeriodicalId":11017,"journal":{"name":"Day 2 Wed, October 13, 2021","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90538283","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}

{"title":"Big Entrance Hole Perforation as New Alternative Approach to Optimize Thru-Tubing Sand Control Technique While Maintaining Reservoir Deliverability for Tunu Gas Reservoir in Unconsolidated Sand Formation","authors":"Rahman Setiadi, Abdel Mohammad Deghati, A. S. Ashfahani, Albert Malvin Richal Dading, Gany Gunawan, Nur Mahfudhin, Zulmi Ramadhana, Sakti Dwitama, R. Rachman, R-Aulia Muhammad Rizky, I. Abidiy, E. Dharma, Rico Pradityo, M. N. Jamal, M. Sobirin, Fata Yunus, William Lodiman","doi":"10.2118/205757-ms","DOIUrl":"https://doi.org/10.2118/205757-ms","url":null,"abstract":"\u0000 Mahakam block with one of its gas fields, Tunu, has been developed for decades. Hundreds of wells were drilled to unlock layered sand reservoirs ranging from unconsolidated to consolidated reservoirs. Through field experience, well architecture is actively developing. The latest architecture, targeting shallow reservoirs only, is called Shallow Light Architecture (SLA). The well is completed with 3.5in production tubing cemented inside a 8.5in open-hole reservoir section. SLA is the default architecture for chemical sand consolidation (SCON) or thru-tubing screens as subsurface sand control.\u0000 Perforation is performed by deep penetration (DP) hollow-carrier guns deployed with double-density to maximize open area and reduce sand production risk. DP charges were used based on the requirement to bypass near-wellbore damage, which is the same practice used in consolidated sand reservoir perforating. As more marginal reservoirs need to be unlocked, big entrance hole (BEH) perforation was initiated for the current sand control optimization alternative by SCON chemical reduction with shorter perforation intervals; and for thru-tubing metal screen performance improvement by placement in front of perforation entrance tunnels with minimum erosion risk.\u0000 BEH was then studied as it has never been used previously in Mahakam with thru-tubing applications. Simulation and pilot well trials were explored to ensure that a short penetration would not significantly impact reservoir delivery on SLA wells. Inflow performance relationship (IPR) analysis resulted in slight additional drawdown compared to the calculated drawdown using DP at 2.5 MMscfd as an average gas rate in current thru-tubing sand control, which was considered acceptable from the operating envelope perspective.\u0000 In total, BEH perforation was executed on ten wells with reservoir permeability range from 220 millidarcy (mD) to an extreme case of 3000 mD. Various SCON treatments were injected at optimized perforation lengths by cutting chemical costs up to 60% with sand-free production at a particular parameter and chemical type. On the other hand, in the application using screens, evaluation was not conclusive due to screen sizing issues for some installations. However, in-situ gas velocity could be reduced to the theoretical erosion velocity limit for a metal screen.\u0000 This new approach to BEH charges utilization has a potential solution optimizing current SCON costs while also reducing erosion risk for the through tubing screen application to improve its performance. By using short penetration of charges, this approach was successfully implemented without jeopardizing reservoir's deliverability.","PeriodicalId":11017,"journal":{"name":"Day 2 Wed, October 13, 2021","volume":"234 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91467441","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}

{"title":"Drilling and Completion Waste Reutilization and Zero Discharge Technology Used in China Bohai Bay","authors":"Kunjian Wang, Pengfei Liu, Xinxin Hou, Pan Wang, Pei Zhu, Mingxuan Hao, Dejiang Li, Qisheng Tang, Qing Wang, Wenchen Ge, Xu Zeng, Hao Zhang, Shihao Zhang, Kejin Chen","doi":"10.2118/205633-ms","DOIUrl":"https://doi.org/10.2118/205633-ms","url":null,"abstract":"\u0000 With the increasingly stringent national environmental rules, waste produced in drilling and completion process is forbidden to be discharged into the Bohai Bay or reinjected into the formation. The current disposal method of drilling and completion waste in Bohai Oil field has some problems such as high cost, low efficiency and high HSE management and control risk. Faced with these problems, drilling and completion waste reutilization and zero discharge technology has been developed and applied in this region.\u0000 In order to reutilize drilling and completion waste which include cuttings circulated from formation, wasted drilling and completion fluids, the following aspects are carried out: Firstly, drilling platform is upgraded to meet the zero discharge requirement: solid control system is modified, cuttings closed transfer system and cuttings treatment system are equipped on the platform to collect and dispose the waste. Meanwhile, recovery and disposal capacity to support different spud drilling are assessed: cuttings transport capacity is up to 15m3/h, which can meet the highest requirements of 12-1/4″ hole drilling when ROP is up to180m/h. Secondly, the well profile is downsized to reduce the production of cuttings, mud and other wastes from the root, which can also improve efficiency and yield cost.\u0000 The field application shows that the amount of the waste has been reduced by 41.39%, 39.86% and 41.52% in first, second and third spud drilling, and average ROP is 35%, 28%, 42% higher than similar wells drilled before. Lastly, in drilling and completion fluids system optimization and reutilization aspects, environmentally friendly drilling and completion fluids with low solid content are developed. The experiment shows that the properties of the liquid phase after solid-liquid separation can be reused, and the solid phase with low water content is easy to pack and transport back to land.\u0000 Drilling and completion waste reutilization and zero discharge technology introduced in this paper has been successfully applied in more than 40 wells, and the volume of waste drilling fluid is reduced by 80%, which is a trade-off between zero discharge and well construction cost. This technology can also be applied in other offshore oilfield which is inevitable as the environmental rules become more and more strict.","PeriodicalId":11017,"journal":{"name":"Day 2 Wed, October 13, 2021","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86467588","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}

{"title":"Study of the Cause of Lost Circulation while Drilling Fractured Carbonates","authors":"A. Ruzhnikov","doi":"10.2118/205806-ms","DOIUrl":"https://doi.org/10.2118/205806-ms","url":null,"abstract":"\u0000 Fractured carbonate formations are prone to lost circulation, which affects the well construction process and has longtime effect on well integrity. Depending on the nature of losses (either induced or related to local dissolutions) the success rate is different when the induced losses can be cured with a high chance, and the one related to dissolutions may take a long time, and despite multiple attempts, the success rate is normally low.\u0000 To have a better understanding of the complete losses across the fractured carbonates, a series of studies were initiated. First, to understand the strength of the loss zone, the fracture closing pressure was evaluated studying the fluid level in the annulus and back-calculating the effect of drilling fluid density. Second, the formation properties across the loss circulation zones were studied using microresistivity images, dip data, and imaging of fluid-saturated porous media.\u0000 The results of the studies brought a lot of new information and explained some previous mysteries. The formation strength across the lost circulation zone was measured, and it was confirmed that it remains constant despite other changes of the well construction parameters. Additionally, it was confirmed that the carbonates are naturally highly fractured, having over 900 fractures along the wellbore. The loss circulation zone was characterized, and it was confirmed that the losses are not related to the fractures but rather to the karst, dissolution, and megafractures. The size and dip of the fractures were identified, and it was proven the possibility to treat them with conventional materials. However, the size of identified megafractures and karst zones exceeding the fractures by 10 times in true vertical depth, and in horizontal wells the difference is even higher due to measured depth. This new information helps to explain the previous unsuccessful attempts with the conventional lost circulation materials.\u0000 The manuscript provides new information on the fractured carbonate formation characterization not available previously in the literature. It allows to align the subsurface and drilling visions regarding the nature of the losses and further develop the curing mechanisms.","PeriodicalId":11017,"journal":{"name":"Day 2 Wed, October 13, 2021","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90098734","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}