Field-Scale Modeling of Smart Completion Tools for Optimum Recovery

Flow control devices (FCDs) like inflow control devices (ICDs) and interval control valves (ICVs) (i.e., equalizer) have increased applications in both conventional and unconventional resources. They have been used to mitigate water or gas coning problems for mature fields in conventional reservoirs, to alleviate premature water breakthrough in naturally fractured reservoirs, and to optimize the steam distribution in heavy oil reservoirs. There have been increased trend in using FCDs in the real field. Previously, complex well models have been implemented in a large-scale parallel reservoir simulator by Tareq et al. (2017). The implementation can simulate an intelligent field contains tens to hundreds of multilateral complex wells commonly referred in the literature as maximum reservoir contact (MRC) wells with mechanical components such as ICVs and ICDs. In this paper, a new framework to model controlling the FCDs in complex well applications will be presented. The implementation is integrated into a complex well model. It can be easily used to model the dynamical control of devices. Simulation studies using both sector model and field model have been conducted. A systematic full-field operation is used for device control applications of smart wells. Successful application of field level controls in smart wells has the benefit of the improved overall GOSP performance.

Advanced Engineering Solutions to Achieve Best in Class Performance in Drilling Extended Reach Dual Lateral Wells in the Sultanate of Oman

A Large Omani Operator successfully achieved best in class performance in drilling extended reach dual-lateral wells in Oman. Turning the legs to achieve the required separation distance and continue drilling to the required depth through a thin fractured reservoir resulted in complex well trajectories and harsh drilling environment. This paper will focus on the newly innovative designs, engineering optimizations and utilizing lean methodology to overcome drilling risks and achieve best in class performance. Rotary Steerable system was utilized to drill the extended reach drilling (ERD) in 3D with continuous proportional steering technology. Advance modeling including lateral shocks, Torque and Drag and BHA design were as well key enablers. Logging while drilling tools supported reservoir mapping and real-time well placement decisions. To excel in lateral applications and overcome harsh drilling environment, a shallow cone tip profile with High Performance cutter bit technology was selected. A focus optimization project using lean tools was performed to map out the undercut process, visualize possible waste, perform root causes analysis and implement countermeasures to eliminate the process waste Regional benchmark showed that the performance of 11 wells drilled since the start of the campaign is located within the best 10% of the benchmark data which is marked as best in class performance. Due to the continues improvement, the campaign manages to reach a learning curve of 30%. Furthermore, the actual production from the wells was 300% more than the forecast. Using the advanced RSS and bit technologies resulted in reducing the Torque values in the lateral section by 30% which effectively increased the reservoir drilled interval by 22%. The designed BHA also managed to complete wells including multi undercuts (up to 6) in one run. One trip Whipstock System for creating the second leg is used as part of the well design. The Whipstock system which is uniquely set in the horizontal tangent section has achieved 100% success rate in setting and retrieving operations. The undercut activities have improved by 50% as a direct result of the optimization Lean project. In addition, utilizing lean methodology resulted in reducing the cost impact of the additional sidetracks (undercuts) which enabled having best reservoir quality and achieving savings over the total cost of ownership TCO. Extended Reach Dual lateral well design was utilized for the first time in PDO operations during this drilling campaign. This paper will present how advance modelling can enable the industry to deliver complex well designs. Additionally, it will introduce the company innovation in implementing the Lean philosophy to optimize the drilling operation.

Lessons Learnt from a Successful Sampling While Drilling Campaign Delivering Formation Oil Samples and Saturation Pressure Measurements in High H2S Carbonates

As island development strategies gain focus for capitalizing deep offshore assets, limitations like fixed slot location bring about the need for drilling extended reach (ERD) wells with multiple drain holes and complex well geometry to maximize the reservoir coverage for increased production. Pressure testing and reservoir fluid sampling operations require long stationary time and pose a risk of differential sticking. Deploying a pressure testing and fluid sampling tool into the drilling bottom-hole assembly (BHA) helps in maintaining well control through continuous circulation and providing measures to retrieve the tool by rotation and jarring in case of pipe sticking. This paper presents the successful deployment of sampling while drilling tools in three ERD wells drilled using water based and oil based muds to acquire representative formation oil samples from a high H2S carbonate reservoir. The formation oil samples were collected immediately after drilling the well to the target depth for limiting the invasion to collect clean samples in shorter pump-out volume and time. After securing the samples, a phase separation test was performed by fluid expansion in a closed chamber to measure the saturation pressure of the oil. A 30-min long pressure build up was also performed for pressure transient analysis to estimate permeability. Formation fluid samples were collected, while pulling out the drilling BHA, within 12-48 hours of drilling the well by pumping out 100-170 liters of fluid from the formation in 4-6 hours. During clean up, absorbance spectroscopy identifies the fluid phases – gas, oil and water. Prominent trends observed in compressibility, mobility, sound slowness and refractive index measurements add confidence to the fluid identification and provide accurate contamination measurements. Single-phase tanks charged with nitrogen were used to assure quality samples for PVT analysis. The sample tanks are made of MP35N alloy and the flow lines are made of titanium that are both H2S resistant and non-scavenging materials and hence, a separate coat of non-scavenging material was not required. In highly deviated wells, sampling while drilling technology can close the gaps of the conventional wireline operation on pipe conveyed logging in addition to saving 5-days of rig time by eliminating the need for conditioning trips, a dedicated run for pressure testing and sampling and minimizing the risk of stuck pipe and well control incidents The results from downhole fluid analysis and PVT lab are compared in this paper. Going forward, this technology can eliminate the requirement of a pilot hole for pressure testing & sampling by enabling sampling in complex well geometries in landing sections and ERD wells. The paper concludes with discussions on suggested improvements in the tool design and capability and recommendations on best practices to align with the lessons learnt in this sampling while drilling campaign.

A Multi-Level Non-Linear Solver for Complex Well Modelling

Complex well model has proved to be important for capturing the full physics in wellbore, including pressure losses, multiphase effects, and advanced device modelling. Numerical instability may be observed especially when the well is produced at a low rate from a highly productive multi-phase zone. In this paper, a new multi-level nonlinear solver is presented in a state-of-the-art parallel complex wellbore model for addressing some difficult numerical convergence problems. A sequential two-level nonlinear solver is implemented, where the inner solver is used to address the convergence in the constraint rate equation, and then the entire complex network is solved using an outer solver. Finally, the wellbore model is coupled with the grid solution explicitly, sequentially, or implicitly. This novel formulation is robust enough to greatly improve the numerical stability due to the lagging in the computation of mixture density in wellbore constraint rate equation and the variation in the fluid composition over Newton iterations in network nonlinear solver. The numerical challenge in the complex well model and the improvement of performance with the new nonlinear solver are demonstrated using reservoir simulation. Models with complex wells running into convergence problems are constructed and simulated. With this novel nonlinear solver, simulation gives much more reliable results on well productions without numerical oscillations and computational cost is much less.

Digitalization in Collaborative Framework : Maintain High Quality Drilling Performance in Mahakam's Complex Well Preparation

Mahakam is a mature gas and oil field that has been in operation since 1966, covering an area of approximately 1500 square kilometers. It is located in East Kalimantan Province, Indonesia and has 7 operating fields. Tunu, Tambora and Handil are fields within the swamp shallow water (Delta), whereas Bekapai, Peciko, Sisi Nubi and South Mahakam are offshore fields with water depths ranging from 45 to 80 meters. The diverse setting of environments requires different methods of site preparation, construction, drilling and logistic. The drilling industrialization necessitates agile and complex well preparation especially in the Deltaic environment, with around 70 wells drilled with three swamp barge rigs each year. In recent drilling development in both Tunu and Handil fields, more shallow wells were drilled. These wells were drilled in the swamp with heavy sedimentation and/or sand banks which necessitated a large amount of dredging and required months of preparation whereas the drilling operation took up to 3 days per wells. The entire well preparation process requires planning, monitoring, and the participation of many team in different entities. Each entity has its own version of well planning database, resulting in data disagreement and lack of data integrity. Thousands of emails are being send and meetings are being organized to guarantee that operations runs well. Due to lack of trustworthy data, personnel movement or team reorganization, it has become serious issues. In 2016, company decided to start the digitalization efforts, by approaching various service company who provides the well planning software. It needed customization to match the corporate needs. However since the digitalization has not yet commonly used by most company, it was then not user friendly, thus several individuals were hesitant to utilize it. An internal team created an application in early 2019. As the business requirement & working flowchart, the team decided to have a clean and mobile-ready yet less complicated form that also enables team collaboration during the design. This ensures that all users, employee from any generation (X, Y, and Z) able to use and enter valid information. Equipped with map visualization, the related entities will be able to have better quick analysis on the condition surrounding wellhead position. The application also implements an adjustable workflow system that able to follow the dynamic of organization structure, ensure each of well planning task is assigned to the correct team. Push notifications are also an important element in this application for keeping the entire team up to date. The application also featured a discussion board and file sharing function, allowing each team to exchange information or files. The manual email exchange has been minimized, and the meeting hour has been reduced significantly. The errors are simply identified and fixed in a single integrated database. The application is continuously improved from well planning only in its early stages into well design to accommodate the whole drilling industrialization process.

Through Barrier Diagnostics to Locate Multiple Barrier Failures in Complex Well Failure Scenario and to Enable Successful P&A

Objectives/Scope A 60-year-old well exhibited a leak at the surface and sustained annuli pressure (SAP) in all three annuli - A, B and C. The age of the well coupled with the symptoms suggested a complex multi-barrier failure scenario that needed to be diagnosed quickly and accurately so that the well could be secured safely. The paper shows how the comprehensive set of downhole diagnostics, including metal and cement barriers integrity assessment, aided in planning and execution of well intervention to secure the indicated failures. The well intervention team selected an approach to investigate the barriers status prior the rig came to the location. Surface diagnostics included evaluation of pressure trends, completion design, leak fluid composition and drilling records analysis which guided the selection of downhole survey. The input parameters for downhole through barrier diagnostics were: Downhole through barrier diagnostics targeted the evaluation of leak paths and failures in well barriers and included: This paper explores the concept, planning, execution and achieved results of the downhole diagnostics performed and how the results were implemented by Operator.

Specialist teams as constituted are unsatisfactory for treating people with personality disorders

Summary It is now becoming standard practice in most advanced economies to provide specialist services for those with personality disorder. Such services, almost exclusively, provide complex well-structured psychological interventions lasting many months for a small number of those with borderline personality disorder pathology. The evidence suggests that these treatments are effective but they can only be provided for a small number of people. However, in every area the numbers of patients with significant personality disorder far exceeds those that are treated, and most of these have other personality disorders. It is argued that the current service system is not working efficiently and should be replaced by one that provides resources and expertise within community teams with some external advice from specialists but no transfer of responsibility to a designated team.

An Automatic Well Planner for Complex Well Trajectories

A data-driven automatic well planner procedure is implemented to develop complex well trajectories by efficiently adapting to near-well reservoir properties and geometry. The procedure draws inspiration from geosteering drilling operations, where modern logging-while-drilling tools enable the adjustment of well trajectories during drilling. Analogously, the proposed procedure develops well trajectories based on a selected geology-based fitness measure using an artificial neural network as the decision maker in a virtual sequential drilling process within a reservoir model. While neural networks have seen extensive use in other areas of reservoir management, to the best of our knowledge, this work is the first to apply neural networks on well trajectory design within reservoir models. Importantly, both the input data generation used to train the network and the actual trajectory design operations conducted by the trained network are efficient calculations, since these rely solely on geometric and initial properties of the reservoir, and thus do not require additional simulations. Therefore, the main advantage over traditional methods is the highly articulated well trajectories adapted to reservoir properties using a low-order well representation. Well trajectories generated in a realistic reservoir by the automatic well planner are qualitatively and quantitatively compared to trajectories generated by a differential evolution algorithm. Results show that the resulting trajectories improve productivity compared to straight line well trajectories, both for channelized and geometrically complex reservoirs. Moreover, the overall productivity with the resulting trajectories is comparable to well solutions obtained using differential evolution, but at a much lower computational cost.

Rewriting Trauma: The Legacy of W.B. Yeats in Marina Carr’s By the Bog of Cats . . .

While a most original and creative playwright in contemporary Ireland, Marina Carr is still unmistakably influenced by her male predecessors. This article will argue that her most renowned work By the Bog of Cats . . . (1998) is a bold rewriting of W. B. Yeats’s Purgatory (1938). Like Yeats’s play, BytheBogofCats . . . focuses on abandonment, betrayal, and murder as its main sources of trauma. While Carr’s play is a direct descendant from Purgatory in terms of its theme, plot, and symbolism, Carr rewrites Yeats’s pathetic, shiftless Old Man into a daring, strong, and responsible woman who may be embittered by her domestic trauma, but instead of escaping, she eventually faces up to her own guilt and crime. Hester is not a flat, helpless victim but a complex, well-rounded woman full of agency, passion, and honesty as well as vices. This way, Carr rewrites both the stereotypical stage image of Irish women and the unredeemable Old Man.