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Suarez-Rivera, Roberto (W. D. Von Gonten Laboratories) | Panse, Rohit (W. D. Von Gonten Laboratories) | Sovizi, Javad (Baker Hughes) | Dontsov, Egor (ResFrac Corporation) | LaReau, Heather (BP America Production Company, BPx Energy Inc.) | Suter, Kirke (BP America Production Company, BPx Energy Inc.) | Blose, Matthew (BP America Production Company, BPx Energy Inc.) | Hailu, Thomas (BP America Production Company, BPx Energy Inc.) | Koontz, Kyle (BP America Production Company, BPx Energy Inc.)
Abstract Predicting fracture behavior is important for well placement design and for optimizing multi-well development production. This requires the use of fracturing models that are calibrated to represent field measurements. However, because hydraulic fracture models include complex physics and uncertainties and have many variables defining these, the problem of calibrating modeling results with field responses is ill-posed. There are more model variables than can be changed than field observations to constrain these. It is always possible to find a calibrated model that reproduces the field data. However, the model is not unique and multiple matching solutions exist. The objective and scope of this work is to define a workflow for constraining these solutions and obtaining a more representative model for forecasting and optimization. We used field data from a multi-pad project in the Delaware play, with actual pump schedules, frac sequence, and time delays as used in the field, for all stages and all wells. We constructed a hydraulic fracturing model using high-confidence rock properties data and calibrated the model to field stimulation treatment data varying the two model variables with highest uncertainty: tectonic strain and average leak-off coefficient, while keeping all other model variables fixed. By reducing the number of adjusting model variables for calibration, we significantly lower the potential for over-fitting. Using an ultra-fast hydraulic fracturing simulator, we solved a global optimization problem to minimize the mismatch between the ISIPs and treatment pressures measured in the field and simulated by the model, for all the stages and all wells. This workflow helps us match the dominant ISIP trends in the field data and delivers higher confidence predictions in the regional stress. However, the uncertainty in the fracture geometry is still large. We also compared these results with traditional workflows that rely on selecting representative stages for calibration to field data. Results show that our workflow defines a better global optimum that best represents the behavior of all stages on all wells, and allows us to provide higher-confidence predictions of fracturing results for subsequent pads. We then used this higher confidence model to conduct sensitivity analysis for improving the well placement in subsequent pads and compared the results of the model predictions with the actual pad results.
Adjei, Stephen (King Fahd University of Petroleum & Minerals) | Elkatatny, Salaheldin (King Fahd University of Petroleum & Minerals (Corresponding author) | Sarmah, Pranjal (email: firstname.lastname@example.org)) | Chinea, Gonzalo (Baker Hughes)
Summary Fly ash, which is a pozzolan generated as a byproduct from coal-powered plants, is the most used extender in the design of lightweight cement. However, the coal-powered plants are phasing out due to global-warming concerns. There is the need to investigate other materials as substitutes to fly ash. Bentonite is a natural pozzolanic material that is abundant in nature. This pozzolanic property is enhanced upon heat treatment; however, this material has never been explored in oil-well cementing in such form. This study compares the performance of 13-ppg heated (dehydroxylated) sodium bentonite and fly-ash cement systems. The raw (commercial) sodium bentonite was dehydroxylated at 1,526°F for 3 hours. Cement slurries were prepared at 13 ppg using the heated sodium bentonite as partial replacements of cement in concentrations of 10 to 50% by weight of blend. Various tests were done at a bottomhole static temperature of 120°F, bottomhole circulating temperature of 110°F, and pressure of 1,000 psi or atmospheric pressure. All the dehydroxylated sodium bentonite systems exhibited high stability, thickening times in the range of 3 to 5 hours, and a minimum 24-hour compressive strength of 600 psi. At a concentration of 40 and 50%, the 24-hour compressive strength was approximately 800 and 787 psi, respectively. This was higher than a 13-ppg fly-ash-based cement designed at 40% cement replacement (580 psi).
Abstract This study presents a hybrid approach that combines data-driven and physics models for worn and sharp drilling simulation of polycrystalline diamond compact (PDC) bit designs and field learning from limited downhole drilling data, worn state measurements, formation properties, and operating environment. The physics models include a drilling response model for cutting forces, worn or rubbing elements in the bit design. Decades of pressurized drilling and cutting experiments validated these models and constrained the physical behaviour while some coefficients are open for field model learning. This hybrid approach of drilling physics with data learning extends the laboratory results to application in the field. The field learning process included selecting runs in a well for which rock properties model was built. Downhole drilling measurements, known sharp bit design, and measured wear geometry were used for verification. The models derived from this collaborative study resulted in improved worn bit drilling response understanding, and quantitative prediction models, which are foundational frameworks for drilling and economics optimization.
Abstract Acquiring acoustic slowness data in open & cased hole and a reliable cement bond log in one run without jeopardising data quality or increasing rig time is desired for fast and optimize data acquisition. This paper reviews the steps taken to ensure acoustic slowness and cement bond data acquisition fulfils the objective, while minimising the cost in an offshore challenging environment for formations with variable acoustic velocities that could be masked by strong casing arrivals. Crossed dipole acoustic logging is typically preferred to acquire within open hole environment for best quality signal. However, due to drilling challenges this could not be done in the subject well. Data was acquired in 6in open hole and 7" liner (8.5 in Open hole behind) cased hole section together in one run. Shear slowness in slow formation requires propagation of the low frequency dipole flexural wave whereas compressional slowness acquisition and cement bond evaluation requires high frequency monopole data. An improved understanding of cased-hole acoustic modes allowed developing the ability to transmit acoustic energies at optimal frequencies in order to acquire formation slowness concurrently with cement bond. Acoustic data quality in cased hole is dependent on cement bond quality. Poor bonding or presence of fluid between casing and the formation inserts noise in the data by damping the acoustic signal. Hence, understanding of the cement bond quality is critical in interpreting the cased hole acoustic data. The low amplitude of the compressional first arrival indicated the presence of cement bonded with the casing. Absence of casing ringing signal at the beginning and presence of strong formation signal in the VDL indicated good bonding of cement with formation. Filtration of the cased hole acquired semblances were necessary to remove the casing and fluids noises. Acquired data shows good coherency and continuous compressional and shear slowness's were extracted from the good quality semblances. This integrated strategy to acquire the formation slowness and to evaluate the cement bond quality and top of cement allowed meeting all objectives with one tool in single run. The risk of casing waves that could have masked the formation slowness signal was mitigated by transmitting acoustic energies at optimal frequencies with wider bandwidth followed by the semblance processing. The effects of borehole ovality, tool centralization, or casing centralization on waveform propagation were studied to supplement the interpretation. The first times strategic logging application in PETRONAS allowed time and cost saving and fulfilled all data acquisition plan. Data quality assurance and decision tree allowed drafting a workflow to assure data quality. This solution showed importance of smart planning to maximise advanced tools capabilities to acquire acoustic slowness data and cement evaluation in single run in offshore challenging environment.
Nanda Kumar, Kishen (Baker Hughes) | Moroni, Luigi (Baker Hughes) | Kongto, Abhijart (Baker Hughes) | Tran Thanh, Bao (Baker Hughes) | Nguyen Hoang, Nghia (Hoang Long & Hoan Vu JOC) | Tran Tuan, Lam (Hoang Long & Hoan Vu JOC) | Do Ngoc, Chau (Hoang Long & Hoan Vu JOC)
Abstract There are many challenges while drilling highly inclined and depleted formations offshore Vietnam that result in various wellbore stability issues such as severe losses, stuck pipe, cavings, tight-hole and pack-offs. These issues may be independent of mud type and can occur when drilling with both oil/synthetic-based and water-based muds. These depleted sections typically consist of sandstones interbedded with claystone & siltstones. Traditionally, the wellbore strengthening fluids solution applied to drill through these sections with synthetic and water-based mud in Vietnam faced limited success. Wellbore strengthening (WBS) is a proven and effective solution especially for narrow-drilling margin and depleted formations. The basic concept of WBS relies on the creation and simultaneous plugging of small fractures with appropriate WBS material. The resulting elevated stress around the wellbore strengthens the borehole by creating an increased hoop stress that leads to an increase in near wellbore stresses. Proprietary modelling software can be used to calculate the pressure induced fracture apertures for wellbore strengthening applications and determine the optimum particle size range to bridge these fractures, allowing fluids to be designed to minimise wellbore instability. This design process was used to optimize material additives to effectively bridge fractures, for wellbore strengthening, and pore throat openings in porous/permeable formations for the prevention of seepage losses and differential sticking. A review of the application procedure identified the optimum method to apply the wellbore strengthening material which would minimise product consumption and reduce well costs. After extensive modelling simulations and testing, this fluid design was applied to drill two challenging wells in Vietnam. This paper presents the process of modelling, based on formation geo-mechanics information, customization and laboratory testing of the fluids design coupled with a successful and economical method of application in the field. Application of this process enabled the operator to drill through the depleted challenging sections with a maximum overbalance pressure of 3,200 psi, conduct logging and coring runs and complete the well at a lower cost and with zero fluids related non-productive time compared to previous wells.
Devadass, Lingges (PETRONAS Carigali Sdn.Bhd) | Kumar, Avinash Kishore (PETRONAS Carigali Sdn.Bhd) | Lau, Chee Hen (PETRONAS Carigali Sdn.Bhd) | Thuzar, Myat (PETRONAS Carigali Sdn.Bhd) | Sion Ban, Tiyor (Baker Hughes) | Kun Kai, Rex Lo (Baker Hughes)
Abstract Good cement bond log and sufficient zonal isolation are important aspects of production wells. Proper cement design and displacement are essential to ensure the cement objectives are met. Well A is one of four development wells, located in East Malaysia. The well was a gas producer, therefore good zonal isolation at the gas intervals are of paramount importance. Coupled with high inclination and formation with narrow pore pressure and fracture pressure margin, ballooning condition was encountered while drilling the reservoir section. These challenging conditions push the boundary of conventional cementing design further to implementation of unique and novel cementing approach to ensure no losses, minimal mud contamination with cement slurry and ultimately produce good zonal isolation. This unexpected conditions of the well lead to re-designing the cement slurry and revamping the placement procedure for the 7" liner across production zone. Operator’s limited experience with cementing in ballooning conditions hampered any reference which could be useful for the job design. Required formation permeability, porosity data, mud flowback volume and duration of mud flowback at static condition were carefully assessed and taken into consideration in the cementing job design and pumping program. Based on the data gathered, an unconventional cement placement technique with specialized spacer and slurry design were proposed Well A, instead of complex back-pressure application technique in order to meet all required cementing objectives. The cementing job was executed as per plan and no losses were observed during the entire cement job. Cement evaluation through cement bond logs indicated that enough isolations across the hydrocarbons zones of interest were obtained. Moreover, cement bond logs also showed good zonal isolation were also attained above and below perforation intervals showing very little contamination of mud backflow into the cement slurry. The cementing technique used proved to be relatively simpler and cheaper as it requires no additional equipment to rig up to execute compared to complex back-pressure technique which done incorrectly may lead to losses or remedial cementing. The successful cementing operation showcased that the planned cementing technique and slurry design were effective for the cementing of abnormal well conditions. This success also highlighted the importance of job pre-planning and necessity to acquire all required data prior to actual operation. The job technique and design was replicated in subsequent wells which had similar well ballooning condition and resulted in great success.
Kamble, Rahul (Baker Hughes) | Kassem, Youssef Ali (ADNOC Offshore) | Indulkar, Kshudiram (Baker Hughes) | Price, Kieran (Baker Hughes) | Mohammed A., Majid (Baker Hughes) | Abid, Kashif (Baker Hughes) | Ahmed, Mostafa (ADNOC Offshore)
Abstract Coring during the development phase of an oil and gas field is very costly; however, the subsurface insights are indispensable for a Field Development Team to study reservoir characterization and well placement strategy in Carbonate formations (Dolomite and limestone with Anhydrite layers). The objective of this case study is to capture the successful coring operation in high angle ERD wells, drilled from the fixed well location on a well pad of an artificial island located offshore in the United Arab Emirates. The well was planned and drilled at the midpoint of the development drilling campaign, which presented a major challenge of wellbore collision risk whilst coring in an already congested area. The final agreed pilot hole profile was designed to pass through two adjacent oil producer wells separated by a geological barrier, however, the actual separation ratio was < 1.6 (acceptable SF to drill the well safely), which could have compromised the planned core interval against the Field Development Team's requirement. To mitigate the collision risks with offset wells during the coring operation, a low flow rate MWD tool was incorporated in the coring BHA to monitor the well path while cutting the core. After taking surveys, IFR and MSA corrections were applied to MWD surveys, which demonstrated an acceptable increase in well separation factor as per company Anti-Collision Risk Policy to continue coring operations without shutting down adjacent wells. A total of 3 runs incorporating the MWD tool in the coring BHA were performed out of a total of 16 runs. The maximum inclination through the coring interval was 73° with medium well departure criteria. The main objective of the pilot hole was data gathering, which included a full suite of open hole logging, seismic and core cut across the target reservoir. A total of 1295 ft of core was recovered in a high angle well across the carbonate formation's different layers, with an average of 99% recovery in each run. These carbonate formations contain between 2-4% H2S and exhibit some fractured layers of rock. To limit and validate the high cost of coring operations in addition to core quality in the development phase, it was necessary to avoid early core jamming in the dolomite, limestone and anhydrite layers, based on previous coring runs in the field. Core jamming leads to early termination of the coring run and results in the loss of a valuable source of information from the cut core column in the barrel. Furthermore, it would have a major impact on coring KPIs, consequently compromising coring and well objectives. Premature core jamming and less-than-planned core recovery from previous cored wells challenged and a motivated the team to review complete field data and lessons learned from cored offset wells. Several coring systems were evaluated and finally, one coring system was accepted based on core quality as being the primary KPI. These lessons learned were used for optimizing certain coring tools technical improvements and procedures, such as core barrel, core head, core handling and surface core processing in addition to the design of drilling fluids and well path. The selection of a 4" core barrel and the improved core head design with optimized blade profile and hold on sharp polished cutters with optimized hydraulic efficiency, in addition to the close monitoring of coring parameters, played a significant role in improving core cutting in fractured carbonate formation layers. This optimization helped the team to successfully complete the 1 high angle coring operation offshore in the United Arab Emirates. This case study shares the value of offset wells data for coring jobs to reduce the risk of core jamming, optimize core recovery and reduce wellbore collision risks. It also details BHA design decisions(4"core barrel, core head, low flow rate MWD tool and appropriate coring parameters), all of which led to a new record of cutting 1295 ft core in a carbonate formation with almost 100% recovery on surface.
Abstract In recent years, we have seen some refined drilling technologies crop up all over the world. These have given rise to implementation of remote centers to work on real time decision making with the wells. While drilling is in process, there are technologies that enable real time transmission of data and voice to and from remote sites, helping in real time intelligent commands and responses. It is hence now possible to form a single team of experts to monitor and control drilling operations. The development of remote operations in the oil and gas industry has evolved over years starting 2004 at different speeds in different regions of the world. For example, it took longer to reach the US land market because of resistance to change at the rig site. The decrease in oil prices in 2014 however, pushed remote operations into existence to reduce cost. Due to challenges such as either oilfield culture, company strategy, human factor, legal factor etc., it was not exactly the "norm". Fast forward to 2020 when the Covid-19 pandemic hit the oil industry into another slump, service companies have been pushed into the remote operations world. To learn with the times, this may be the new norm and maybe an excellent one. Many service companies have successfully performed operations wells globally increasing not only the efficiency of wellsite operations but also contributing to cost optimization and safety. During implementation, it is observed that remote operations are less a technical challenge, and more a value challenge requiring confidence from all stakeholders. In terms of drilling and operational efficiency, the results observed globally are significant, with fewer trips for M/LWD failure, as well as significant reductions in M/LWD NPT while drilling. This paper discusses the implementation of remote operations at global scale, lesson learnt on day-to-day basis, optimization opportunities, business workflow, positives such as business continuity, safety aspect and last but not the least, the environmental impact. The paper also talks of changes and effects of Covid-19 Pandemic on these operations. Remote operations prepare us well for such pandemic and it may be the safer way to operate now on. Also discussed are the keys to successful remote operations and various examples of remote operations establishments throughout the globe. Lastly a SWOT analysis is done to conclude how remote operations will help operators to add more value to operations and show that remote operations is the new future.
Kumar, Suman (PETRONAS Carigali Sdn. Bhd.) | Chandrakant, Ashvin Avalani (PETRONAS Carigali Sdn. Bhd.) | Salleh, Fairus Azwardy (PETRONAS Carigali Sdn. Bhd.) | Jamil, Ahsan (Baker Hughes) | Ibrahim, Zulkifli (Baker Hughes) | Chang, Claire (PETRONAS Carigali Sdn. Bhd.) | Chiew, Kwang Chian (PETRONAS Carigali Sdn. Bhd.)
Abstract Mature Field-D has produced at recovery factor (RF) less than 20% due to its geological complexity. As per re-development plan, four wells were drilled from newly built platform in 2020. Each well was completed with combination of oil and gas zones with maximum five zones per well. The gas zone is utilized as an in-situ gas lift, considering gas lift gas shortage and anticipated future requirement for artificial lift upon pressure depletion and water breakthrough. All-electrical inflow control valve (ICV) and permanent downhole gauges (PDG) has been installed across each respective oil & gas zone. The system serves to provide zonal production control to mitigate high producing gas-oil-ratio (GOR) or water breakthrough zones. Single string multi-zone ICV completion enables maximum production from layers with varying reservoir properties and pressure depletion. In addition, gas zones completed with ICV enables cost-effective application of in-situ or well-to-well gaslift, facilitates future non-associated gas production for gas monetization project as well as gascap blowdown opportunities. Application of all-electric smart completion has enhanced proactive surveillance and provided greater production control flexibility resulting in higher production than target. From the downhole data obtained from PDG, wells and network model were updated with good certainty and used to further optimize production at well, platform and field level. Multiple ICV configuration were simulated to maximize oil, minimize gas and water production considering facilities limitation in terms of liquid handling and gas processing to reduce carbon footprint. The gas zones have been utilized for in-situ gas lift using ICV. The smart completion has also enabled efficient unloading facilitated by real-time data acquisition and production control through ICVs leading to additional cost savings. It marks the first installation of an all-electric smart completions offshore Malaysia and Asia Pacific. This paper will explain the functionality of all-electric ICV system and outlines the methodology undertaken to optimize production at well, platform and field level utilizing industry recognized well and network models.
Abstract Over the past years the usage of coiled tubing as a prefer method to deploy long and heavy guns in highly deviated wells has been widely spread in the oil industry to provide a single run without killing the well, perforate in underbalance conditions, reduce risks and improve job efficiency. The three wells are located in the Caspian Sea. In two wells, the objective was to isolate lower intervals and perforate a new zone through tubing and casing between two packers. On the other well, the objective was to perforate a new interval through casing after running a new completion and isolate lower production zones. Due to the challenges involving gross length of the new intervals, guns size, well deviation and live deployment needs several techniques were evaluated. The best approach was to use an Advance Live-Well Deployment (ALWD) system to deploy and retrieve the guns with a tube wire-enabled Coiled Tubing Telemetry (CTT) system focus on both safety and cost saving compare with conventional wireline perforating. Extensive job planning involved coiled tubing (CT) simulations to reach target depths, shock loading modeling to ensure forces are within CT string limitations, system integration test to verify deployment/reverse technique procedure and system communication to electrically activate guns. CTT integrated sensor assembly was used during deployment/reverse operation with a tension, compression and torque (TCT) sub-assembly to monitor accurate upward/downward forces. In addition, CTT logging adapter assembly was used for depth correlation and electrical guns activation. The ALWD system; composed by connectors and deployment blow out preventor (BOP), prove to be an efficient way to run, perforate and retrieve gross intervals of 212 m, 246 m and 104 m with guns successfully. During all these jobs several lessons learnt were created in order to improve the deployment/reverse procedure for future jobs including not only operational steps but also deployment/reverse bottom-hole assembly (BHA) configurations. Based on the success of these case histories, the ALWD combined with CTT system has been proven to be the preferred method when dealing with long perforation intervals in life well conditions, thru-tubing environment.