Day 2 Wed, March 27, 2019最新文献

{"title":"Successful Treatment and Reuse of Flowback Guar Frac-Fluid in Ordos Basin and Associated Cost Savings to Operators","authors":"Ningjun Li, Ziqiong Zheng, P. Guo, Xipeng Hao, Bingwei Chen, Yao Ren","doi":"10.2523/IPTC-19555-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19555-MS","url":null,"abstract":"\u0000 Ordos basin is known for its tight sandstone formations and fracturing has been the most effective approach to improve production[1,2]. With increasing stimulation activities, water consumption, and associated water cost, flowback fluid volume also increased dramatically. Successfully treat the flowback fluid and the reuse of the treated fluid in making new frac fluid are keys to improve stimulation economics and protect the environment. However, treatment and reuse of commonly used guar frac fluid system remains a significant challenge to operators and service companies.\u0000 To successfully treat and reuse flowback fluid in Ordos basin, two major obstacles have to be overcome: First, in the fracturing process, the local common practice is to add the entire designed amount of gel breaker at the end of propant pumping job, to avoid sand plugging and sanding out. This incorrect, but common practice results in incomplete breaking of gel of the frac fluid, which inevitably flows back leading to greatly increased difficulties in flowback fluid treatment. Secondly, organic boron crosslinking agent is widely used as crosslinking agent in the guar fluid system in this area. As boron compounds are extremely difficult to be removed during flowback fluid treatment, proven treatment methods alone cannot make the treated water reusable in making new frac fluids.\u0000 Technology and processes were developed to manage four key factors that affect the performance of guar frac fluid configured with treated flowback fluid: a) Metal ions, b) Bacteria, c) Breaking agent, d) Crosslinker. Mobile units developed in association with treatment processes and agents also help avoid secondary pollution from the transportation of fresh and flowback fluid. In 2017 and first quarter of 2018, more than 15,000 cubic meters of flowback fluid have been successfully treated and reused. One third of the treated water was guar frac fluid and was reused in making new frac fluid, reducing the need for fresh water significantly. Fracturing service company conducted tests on the treated water and found that the performance of the fluid configured with the treated water completely satisfy the requirements of the SY/T6376-2008 \"General Technical Requirements for Fracture Fluid\" and SY/T 5523-2016 \"Oilfield Water Analysis Method\" standard. Frac fluid configured with the treated water was successfully applied to the stimulation jobs of horizontal wells, resulting in double savings to the operators: purchase of fresh water and transportation of flowback fluid (to treatment centers) and fresh water, also avoided secondary environmental impacts such road safety hazard and fluid seepage.\u0000 With the treatment and reuse of flowback fluid, savings up to 8% of total frac costs per well were observed which could lead to 100+ million RMB within 2018 alone. Most importantly, the technology can effectively relieve environmental pressure and reduce the need of fresh water which is a scarce in this area.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128132625","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":"Chemical Treatment Scenario of Produced Fluid by ASP Flooding Using NaOH, Alkylbenze Sulfonate and HPAM at Daqing Fields","authors":"Di Wu, Wenjie Liu, Xun Cai, Xiangchun Meng, Yuepeng Yang, Sen Lin, Shaohui Zhang, Cong Wang, Huiping Zhang, L. Yinghui, F. Zhao, Xin Zhang","doi":"10.2523/IPTC-19243-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19243-MS","url":null,"abstract":"\u0000 ASP flooding using NaOH, alkylbenze sulfonate and HPAM has been put into industrial application at Daqing Fields. While significantly increasing oil recovery, it has also brought in new challenges for the handling of produced fluid such as precipitation of new mineral particles in the aqueous phase, scale deposition, foam, stable reverse emulsion in both produced fluid and produced water, and expanded rag layers in electrostatic treaters. To facilitate handling of the produced fluid and produced water by ASP flooding, numerous chemicals have been developed and applied, such as antifoams, demulsifiers, dual functional demulsifiers and reverse demulsifiers, sulfide scavengers, chelatants, and alkalines. A comprehensive scenario for the application of the above mentioned chemicals has been developed and applied in the handling of ASP flooding produced fluid at Daqing Fields. The scenario consists of continuous injection of dual functional demulsifier and reverse demulsifiers, antifoams at the inlet of production separators or into the produced water heated, recycled back to wellsites and blended into wellhead produced fluid to facilitate its flow to oil gathering stations, continuous injection of chelatant and alkaline into the produced water recycled back to be the wellheads, temporary injection of demulsifier and alkaline into the feed of bath heaters upstream of electrostatic treaters on an as-needed basis, batch injection of sulfide scavenger into the produced water recycled back to the wellheads, as well as batch injection of sulfide scavenger and alkaline into the feed or backwashing water of media filters treating produced water. The chemical treatment scenario has been successfully applied in 4 ASP projects using NaOH, alkylbenze sulfonate and HPAM at Daqing fields, significantly improving the performances of surface production facilities handling ASP flooding produced fluid.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130755154","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":"4-D Geomechanics Modelling for Potential CO2 Storage Site in Malaysia – Fault Reactivation and Maximum Pressure Injection Limit","authors":"N. N. Kamaruddin, Kevin Ging Ern Teng, I. H. Musa, C. Tan","doi":"10.2523/IPTC-19491-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19491-MS","url":null,"abstract":"\u0000 This paper presents a study on the risk associated with CO2 injection in geological storage and fault reactivation through a comprehensive workflow for determining the feasibility of CO2 storage campaign in carbonate reservoir in Malaysia. The study includes constructing a 4-D coupled reservoir geomechanical model and developing a workflow that can be used to evaluate geomechanics risks associated with carbon capture and storage (CCS) by outlining results and findings that drive key decisions in the planning of CCS strategy.\u0000 The workflows aims to better delineate and enumerate the risks with CCS as it constructing and calibrating single well models by corroborating numerous inputs including stringent laboratory testing data and drilling analysis, and combining with structural model and reservoir model to create a field wide 4-D geomechanical model using advanced time lapsed geomechanics simulation. Coupled simulations with the dynamic reservoir model provided predictions of the fault stability by considering fault deformation. The paper further highlights the geomechanics evaluation consideration (economics and engineering trade-off) in designing maximum safe injection pressure for CO2 sequestration program.\u0000 The results of the study show fault condition subjected to different time-steps of the coupled simulation during depletion and injection. At each time-step, the development of plastic shear strain and absolute displacement are plotted and risks associated with the change in reservoir pressure are assessed and quantified. Different injection plans are modelled to determine the impact on final storage capacity, long term fluid containment and upper safe injection limit to avoid breaching the caprock.\u0000 The study offers the utilization of the latest techniques in 4-D coupled geomechanical modelling which reduced the study time and cost significantly, making it affordable for in-time solution for decision making. The paper also aims to encourage the consideration of the applied novel workflow involved in CCS strategye valuation focusing on risk assessment which ultimately will affect reservoir maximum safe injection limit, capacity, long term storage safety, and monitoring program to mitigate potential geohazard leakage.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133490837","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":"Comprehensive Identification Technology of Atypical Bright Spot Oil Reservoirs in Deep Water Area of Eastern South China Sea","authors":"Zhiye Li, Jie Liu, Zhongtao Zhang, Zhaominng Chen, Bao-jin Liu, N. Shi","doi":"10.2523/IPTC-19540-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19540-MS","url":null,"abstract":"\u0000 A series of light oil fields which are characterized by shallow burial, good physical property have been discovered through latest exploration in Baiyun Depression of Pearl River Mouth Basin. However light oil reservoir is \"Atypical bright spot\" reservoir. The light oil-bearing and gas bearing structures in the seismic section are characterized by \"bright spot\" reflection, and the difference of elastic parameters is not obvious. Traditional methods are inefficient to discriminate oil, gas and water. Aiming at the above problems, the fluid rock physical interpretation version is rebuilt through the analysis of Gassmann fluid factor based on two-phase medium petrophysics theory and the elastic parameters of the P-wave impedance. Then the three fluid properties of oil, gas and water are classified by direct inversion technique based on elastic impedance. The real data processing and exploration practice have proved the feasibility and validity of this method which is instructive to deep water exploration.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128869460","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":"Novel Workflow to Characterize Secondary Porosity in Carbonate Reservoir, Case Study of Tuban Formation - Indonesia","authors":"Adeyosfi Merza Media, M. Muhajir, Haidar M. Wahdanadi, Purwanto Agus Heru, P. Anugrah, Juandi Dedi","doi":"10.2523/IPTC-19409-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19409-MS","url":null,"abstract":"\u0000 Most of sedimentary basins in Indonesia contain productive carbonate reservoirs. Geologically, the reservoirs are mostly part of a reef complex and carbonate platform, with basinal areas situated mainly in the back arc of the archipelago. Many of the productive carbonate reservoirs have dual porosity systems with widely varying proportions of primary and secondary porosity. Carbonates of the Tuban formation in Platinum field represent two carbonate buildups identified with similar effective porosity but different productivity. This paper describes a method for characterizing secondary porosity distribution at the wellbore and field scales to address the productivity difference between the northern and southern carbonate buildups in this field.\u0000 To resolve the challenges in characterizing secondary porosity in a carbonate formation, an integrated workflow was developed that consists of combination of quantitative and textural analysis based on borehole images at the single-wellbore scale and the seismic inversion result to control lateral distribution at the field scale. Analysis based on borehole image log provides high-resolution porosity characterization based on its size, interconnectivity, and type. The result of the single-wellbore analysis will be distributed at the field scale with control of a seismic attribute such as acoustic impedance (AI). Acoustic impedance is built with stochastic seismic inversion to provide a higher-resolution result compared to the deterministic seismic inversion method.\u0000 The result of the analysis based on borehole images at the single-wellbore scale shows most of the northern carbonate buildup wells demonstrate high development of porosity from interconnected vugs, leading to a relatively high permeability interval. In contrast, the southern carbonate buildup wells demonstrated low secondary porosity development. Low secondary porosity development is related to cemented zones and the predominance of claystone facies in a well. Later, the result of the single-wellbore scale analysis was distributed at the field scale with seismic attribute control such as AI. The Platinum field shows a negative correlation between AI and porosity with a value of -0.769; hence, the acoustic impedance from stochastic seismic inversion can be used to control the porosity distribution. The secondary porosity model shows a distinct difference between the northern and the southern carbonate buildups. The northern carbonate buildup has higher average secondary porosity compared to the southern carbonate buildup. The result was confirmed with production data; the northern carbonate buildup has higher productivity compared to the southern carbonate buildup.\u0000 This integrated workflow provides a comprehensive and high-resolution analysis of secondary porosity distribution at the single-wellbore scale and the field scale. Thus, this workflow can reduce uncertainty during reservoir characterization, well placement, and production planning.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"189 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115423616","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":"Consistent Evaluation of the Organic Content of the Qusaiba Shale Using Digital-Rock Methodology","authors":"M. Abouelresh, M. Khodja, Rizwanullah Husseini, H. Al-Mukainah, Abdelwahab Ali","doi":"10.2523/IPTC-19085-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19085-MS","url":null,"abstract":"\u0000 Unconventional hydrocarbon resources continue to engender increasing attention as potential energy sources. This is reflected in the ongoing research aiming at gaining a better understanding of potential unconventional reservoirs. In this note, we describe a study focused on an organic-rich, potential gas-producer shale from Saudi Arabia, namely the Qusaiba Shale. The study aims, in particular, to quantify organic matter content, mineral content, and porosity using digital-rock methodology validated by laboratory measurements.\u0000 Rock plugs are selected from whole cores representative of the organic-rich, Qusaiba Shale. The core plugs are first digitized using high-resolution μ CT scan and the obtained 3D models are segmented to separate the total organic content (TOC) volume, rock matrix, and pore network. X-ray diffraction (XRD), X-ray fluorescence (XRF), and quantitative scanning electron microscopy (SEM) analyses are undertaken to determine elemental and mineralogical composition. To characterize porosity at a level adequate for shale, the samples also undergo SEM imaging, as well as nuclear magnetic resonance (NMR) analysis. Subsequently, numerical upscaling is applied and comparison of numerical and experimental results is performed.\u0000 Petrography and mineralogy analyses show that the major mineral components of the Qusaiba Shale samples are silica, feldspars, mica, clay, and pyrite. SEM imaging reveals that, at the nanoscale, the samples are characterized by a variety of pore types, sizes, and morphologies. Porosity comes in two types: intergranular and organic, with intergranular porosity being the dominant type. Compaction and horizontal alignment of the detrital mineral grains control the development of intergranular porosity while the distribution of organic particles, as well as their maturity, are the key factors controlling the formation of organic porosity. Integrating SEM images, high-resolution X-ray scans, and NMR measurements provides the information utilized to quantitatively determine the mineral and organic contents of the samples. Preliminary results exhibit a consistent agreement between the upscaled digital-rock-based estimates and the experimental measurements.\u0000 The main contribution of this study is an affordable, Digital Rock Physics (DRP)-based characterization of the organic content, mineral content, and pore-network structure of samples representative of Saudi Arabia's potential shale gas reservoirs that is consistent with laboratory measurements.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124584506","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":"Investigation of Anhydrite Dissolution as a Potential Low Salinity Waterflooding Mechanism Using Carbonate Reservoir Rocks","authors":"Takaaki Uetani, Hiromi Kaido, H. Yonebayashi","doi":"10.2523/IPTC-19133-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19133-MS","url":null,"abstract":"\u0000 Many mechanisms have been proposed for low salinity waterflooding enhanced oil recovery (EOR) in carbonate rocks over the last decade, and they are still in debate. One suggested mechanism is the dissolution of anhydrite (CaSO4) mineral from a rock material, which generates sulfate ions in-situ, and subsequently acts as a wettability modifier chemically. Another suggested mechanism is the increase in permeability due to mineral dissolution. Primary objective of this work was to verify whether dissolution of anhydrite could be the key low salinity waterflooding EOR mechanism.\u0000 Spontaneous imbibition tests were conducted using six rock samples from two carbonate oil reservoirs. The first reservoir rock contains anhydrite, while the second reservoir does not contain anhydrite. If anhydrite dissolution is the key mechanism, then the amount of increased oil recovery due to low salinity brine should correlate with the amount of anhydrite dissolved from the rock. Our experimental results, however, did not suggest such a relationship. Hence, anhydrite dissolution was considered unlikely as the key mechanism of low salinity EOR for the crude-oil, brine and rock (COBR) system used in this study.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"232 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114432898","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":"Intelligent Under Reamer A Solution for Lean Casing Profile","authors":"Aik Loong Khaw, Ngoc Thanh Phuong Nguyen, Q. A. Vu, Dennis Miguel","doi":"10.2523/IPTC-19539-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19539-MS","url":null,"abstract":"\u0000 In Vietnam, there was a need of a lean surface casing due to restricted drift inside diameter (ID). The 2nd slot of the splitter conductor only have 13-1/2\" ID max pass through. The practical option is to drill with 12-1/4\" bit and open to 14-1/2\" hole to set 11-3/4\" casing OD. Similar reasoning for the intermediate hole that will require to under ream the hole from 10-5/8\" bit to 12-1/4\" hole and set 9-5/8\" casing OD. Although these under reaming operations are commonly practiced, the technical limitations are still inefficient and compromising. Conventional reamers still have limited activation/deactivation cycle for operational flexibility and long rathole of the reamer to bit depth for casing shoe placement.\u0000 The long awaited technology is now available with the presence of intelligent reamers that have unlimited activation & deactivation cycles and can be placed directly above the rotary steerable system for shortest possible rathole. The setup is to combine two intelligent reamers in a single BHA. The 1st reamer placed strategically on top of the MWD & LWD tools while the 2nd reamer is directly above the rotary steerable system tool. As both reamers can be both activated and deactivated through downlinking, the reamer has to be activated simultaneously to control the risks associated with hole opening and LWD data acquisition. The 1st intelligent reamer will be activated first while drilling the section formation and the 2nd intelligent reamer will then be activated at section TD to ream and shorten the rathole. For the purpose of cleaning the hole effectively, both reamers can be deactivated to execute high flow and RPM without creating new cuttings from the reamer blades and avoid making a bigger hole at the low side.\u0000 This enabled shoe to shoe drilling while under reaming and achieving less than 10m rathole. These operational capabilities saved at least 50% of the section rig time compared to having a 2 trip system. Combination of reduced casing shoe rathole and open hole exposure mitigated the well bore instability risks and helps in managing mud weight for both hole section intervals. The unlimited activation cycle provided flexibility in operations particularly in dealing with hole cleaning and wiper trips. Plus, the intelligent reamer provides realtime reamer diameter which gives confidence on the drilled hole size for casing running preparation and decisions.\u0000 Intelligent reamers have unique tool features that differentiate from the rest of current industry technologies. This feature helps to eliminate the risk of under-reamer balling, which improve the rate of penetration. The success of the operation has spread throughout operators in Vietnam, and now the intelligent reamer is considered as a game changer application in drilling lean casing profiles.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125896388","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":"Application of the Broadband Seismic Acquisition in Huizhou Sag, Pearl River Mouth Basin, China","authors":"Zhaoming Chen, Dengfeng Yang, Weihua Luo, Yingjing Xu","doi":"10.2523/IPTC-19086-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19086-MS","url":null,"abstract":"\u0000 The Huizhou sag of the Pearl River Mouth Basin is one of the first areas to try to operate the broadband seismic acquisition with variable-depth streamer in the offshore seismic exploration of China. Different from the conventional acquisition, the streamer of the broadband seismic acquisition is depth variable. Through broadband seismic acquisition and processing, the ghost waves can be effectively identified and removed to broaden the seismic frequency band. In order to make good use of the broadband seismic data, we firstly test the reliability of broadband seismic data through a forward model and post-stack seismic inversion. Then the targets in Huizhou sag is taken as an example to do the inversion experiments. The results show: the broadband seismic acquisition can effectively suppress the interference of the wavelet side-lobe and the multiples and can obviously improve the signal-to-noise ratio; meanwhile, it can enhance the accuracy to identify the thickness of the reservoir and can improve the fidelity of seismic data.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"437 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126125009","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":"Resolving Torsional Vibration in Horizontal Limestone Reservoirs Prevents Severe Equipment Damages","authors":"Adil Al Busaidi, A. Hawy, A. Omara, A. Lawati, R. Bautista, Muhannad Awadalla, Ghaida Abdullah Salim Al Ghaithi, Z. Chibani, Suroor Al Jamaei","doi":"10.2523/IPTC-19058-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19058-MS","url":null,"abstract":"\u0000 Torsional vibration (also known as stick and slip) is a major contributor to equipment failures and severe damage when drilling the 6 1/8-in. lateral limestone Shuaiba reservoir section in PDO North Oil fields. This paper examines multiple factors that can affect the severity of stick and slip and measures their actual impact. These factors include bit/bottomhole assembly (BHA) design and formation/mud properties. The effect of a software plugin to an automated drilling system that was designed to mitigate the effects of stick and slip was also examined.\u0000 Initially, drilling dynamics data available for the lateral Shuaiba reservoir were analyzed to evaluate the levels of torsional vibration. Several proposed design changes to reduce the torsional vibration were then modeled separately using finite element analysis (FEA) to predict their dynamic behavior. Trials were conducted, and the impact of independently changing each factor in the overall torsional vibration was assessed. Data were collected from over 40 horizontal wells drilled in the same reservoir. In each set of trials, identical drilling conditions were maintained while changing a single factor.\u0000 The analyzed legacy set of well data showed high levels of torsional vibration (stick and slip) in the lateral section for different fields that share nearly the same reservoir characteristics and bit/BHA design. Using a similar formation profile, the FEA modeling results suggested that stiffening the drillstring and using heavier sets of PDC bits would greatly reduce the torsional vibrations while maintaining a good rate of penetration. When these changes were applied, actual data were analyzed to measure the improvement. Additionally, the analysis found that specific formation characteristics such as formation density highly contribute the severity of torsional vibration.\u0000 Modeling also suggested that applying higher torque to the bit reduces its RPM fluctuations and allows for lower surface parameters. This, in return, reduces the amplitude of the torsional vibration. Over eight trials were analyzed, and significant reductions in both the measured torsional vibrations levels and equipment failures and damages were seen.\u0000 Finally, the effect of utilizing a software plugin to an automated drilling system to mitigate stick and slip when drilling the 6.125-in. lateral limestone reservoir was examined. Like the other proposed solutions, the remaining factors were kept constant.\u0000 The paper offers a rare case study specific to lateral limestones reservoirs, where interbedded layers are a common contributor to the severity of torsional vibrations. The results and conclusions are based on downhole high-resolution data to calibrate finite element models to provide fit-for-purpose solutions. The results eliminate much of the theoretical explanations about root causes of torsional vibrations in limestone reservoirs.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127428051","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}