Research of inflow control devices for estimation of application in intellectual well

Ensuring the completeness of oil and gas production from the subsoil by using modern techniques and technologies for controlling the inflow into the well is an urgent task, especially for wells with long horizontal ends. Inflow control devices (ICD), used in conjunction with packers and downhole measurement devices, are part of such systems, covered by the concept of «smart well». In general, such systems make it possible to control the inflow (flow rate) in individual intervals of horizontal wells or in vertical wells of multilayer fields while operating simultaneously in order to optimize production without additional downhole operations in real time. Keywords: inflow control device; horizontal well; intelligent well.

Improved Simulation Efficiency for Optimising Inflow Control Device Completions Using Suitably Upscaled Models and Parallel Global Search Optimisation Techniques

Inflow Control Device (ICD) completions can improve well performance by adjusting the inflow profile along the well and reducing the influx of unwanted fluids. The ultimate aim of using ICD completions is to provide maximum oil recovery and/or Net Present Value (NPV) over the life of the field. Proactive ICD optimisation studies use complex reservoir models and high-dimensional nonlinear objective functions to find the optimum ICD configurations over the life of the field. These complex models are generated from fine scale detailed geological models to accurately capture fluid flow behaviour in the reservoir. Although these high-resolution geological models can provide better performance predictions, their simulation runtimes can be computationally expensive and time consuming for performing proactive ICD optimisation studies that often require thousands of simulation runs. We propose a new workflow where we use upscaled and locally refined models coupled with parallelised global search optimisation techniques to improve the simulation efficiency when performing ICD optimisation and decision-making studies. Our approach preserves the flow behaviour in the reservoir and maintains the interaction between the reservoir and the well in the near wellbore region. Moreover, when coupled with parallel optimisation techniques, the simulation time is significantly reduced. We present an in-house code that couples global search optimisation algorithms (Genetic Algorithm and Surrogate Algorithm) with a commercial reservoir simulator to drive the ICD configurations. We evaluate the NPV as the objective function to determine the optimum ICD configurations. We apply and benchmark our approach to two different reservoir models to compare and analyse its efficiency and the optimisation results. Our analysis shows that our proposed approach reduces the run time by more than 80% when using the upscaled models and the parallel optimisation techniques. These results were based on a standard dual-core parallel desktop configuration. Additional results also showed further reduction in run time is possible when employing more processors. Additionally, when testing different ICD completion strategies (ICDs in producers only, ICDs in injectors only, and ICDs in both producers and injectors), the NPV can be increased by 9.6% for the optimised ICD completions. The novelty of our work is rooted in the much-improved simulation efficiency and better performance predictions that supports ICD optimisation and decision-making studies during field development planning to maximize profit and minimize risk over the life of the field.

Agile Smart Completion Application for Effective Water Production Control in Heterogeneous Carbonate Reservoir in Abu Dhabi Offshore Reservoir

This paper provides the learnings from a successful application of a smart completion in a complex heterogeneous carbonate reservoir. It details the study, planning, coordination, and implementation process of two pilot wells by a multidisciplinary team, and pilot production performance results, illustrating the success. First, to select an optimum completion design for the field, multi-segment well option and local grid refinement option were applied to the reservoir simulation model including calibration of faults/fractures. Second, based on the modified model, sensitivity analysis was conducted; 1) by selecting different types of completion including Open-hole, blank pipes (BP), compartmentalized slotted liners (SL), inflow control device (ICD) and hydraulic flow control valve (FCV); 2) by optimizing the number of compartments (packer and blank pipe placements for all cases), and ICD / FCV numbers and nozzle sizes. Using the data from the modeled cases, economic analysis was conducted, which indicated that the ICD in conjunction with sliding sleeves (SSD) was the best option. Two candidate wells were selected to cover the variation of reservoir characteristics: one well representing the heterogeneous part of the reservoir with high-density of faults, fractures and kurst, and another one representing the relatively homogenous part of the reservoir suffering from heel to toe effect. A multidisciplinary implementation team was set up to align all stakeholders on subsurface requirements, following up the completion design, coordinating material procurement and logistics for mobilizations, daily drilling operations follow-up, real-time logging data interpretations and completion design adjustment. Evaluation of the two pilots’ results based on predefined KPIs during the study, exceeded overall expectations.

Novel Active Inflow Control Technology for Optimized Flow and Reduced Intervention

Summary Integrating a flow control sliding sleeve into a sand screen can provide multiple advantages to the user in controlling the production inflow, but it comes with an increased completion cost as well as an increase in the number of interventions required when it is time to operate those valves. Especially in long horizontal wells, this can become time-consuming and inefficient. A few technologies exist to address this issue, but they either are too complex or require specialized rigging equipment at the wellsite, which is not desirable. As described herein, a unique, fit-for-application modular sliding sleeve sand screen assembly with dissolvable plugs was developed that eliminates the need for washpipe during run-in-hole (RIH) and allows flow control from several screens by means of a single sliding sleeve door (SSD), thereby also optimizing the subsequent intervention operations by reducing the number of SSDs in the well. The design and field installation of these modular screens is presented in this paper. The new modular sand screen consisted of an upper joint, modular middle joint, modular middle joint with an inflow control device (ICD) integrated into an SSD (with optional dissolvable plugs), a lower joint, and novel field-installable flow couplings between them. The design allows for any number of non-ICD/SSD screen joints to be connected to any number of ICD/SSD joints in any order. A computer-aided design was followed to achieve all the operational and mechanical requirements. Computational fluid dynamics (CFD) was used to optimize the flow performance characteristics. Prototypes were manufactured and tested before conducting successful field trials. The design process, development, and field installation results are presented herein.

From Completion Design to Efficiency Analysis of Inflow Control Device: Comprehensive Approach for AICD Implementation for Thin Oil Rim Field Development Efficiency Improvement

The complex interbedded heterogeneous reservoirs of the Severo-Komsomolskoye field are developed by horizontal wells in which, as part of the pilot project's scope, autonomous inflow control devices (AICD) are installed to prevent early coning and gas breakthroughs in long horizontal sections and reduce sand production, which is a problem aggravated by an extremely low mechanical strength of the terrigenous deposits occurring in the Pokur formation of the Cenomanian stage in this area. The zones produced through AICDs are separated by swell packers. The issue of AICD effectiveness is discussed in the publications by Solovyev (2019), Shestov (2015), Byakov (2019) and some others. One of the methods used for monitoring horizontal sections with AICDs is production logging (PLT). However, due to the complexity of logging objectives, the use of conventional logging techniques makes the PLT unfeasible, considering the costs of preparing and carrying out the downhole operations. This paper provides some case studies of the Through-Barrier Diagnostics application, including passive spectral acoustics (spectral acoustic logging) and thermohydrodynamic modelling for the purpose of effective estimation of reservoir flows behind the liner with AICDs installed and well integrity diagnostics. As a result of the performed diagnostics, the well completion strategy was updated and optimised according to the log interpretation results, and one well intervention involving a cement squeeze with a straddle-packer assembly was carried out.

Innovative Washpipe Free Circulating ICD Delivers Reduced Well Construction Costs

This Extended Reach Drilling (ERD) field re-development of a giant offshore field in the United Arab Emirates (UAE) requires in most cases extremely long laterals to reach the defined reservoir targets. However, certain areas of the field show permeability and / or pressure variations along the horizontal laterals. This heterogeneity requires an inflow control device (ICD) lower completion liner to deliver the required well performance that will adequately produce and sweep the reservoir. The ICD lower completion along with the extremely long laterals means significant time is spent switching the well from reservoir drilling fluid (RDF) non-aqueous fluid (NAF) to an aqueous completion brine. To reduce the amount of rig time spent on the displacement portion of the completion phase, an innovative technology was developed to enable the ICDs to be run in hole in a closed position and enable circulating through the end of the liner. The technology uses a dissolvable material, which is installed in the ICD to temporarily plug it. The dissolvable material is inert to the RDF NAF while the ICDs are run into hole, and then dissolves in brine after the well is displaced from RDF NAF to completion brine, changing the ICDs from closed to an open position. The ability to circulate through the end of the liner, with the support of the plugged ICDs, when the lower completion is deployed and at total depth (TD), enables switching the well from RDF NAF drilling fluid to an aqueous completion brine without the associated rig time of the original displacement method. The technique eliminates the use of a dedicated inner displacement string and allows for the displacement to be performed with the liner running string, saving 4-5 days per well. An added bonus is that the unique design allowed for this feature to be retrofitted to existing standard ICDs providing improved inventory control. In this paper the authors will demonstrate the technology and system developed to perform this operation, as well as the qualification testing, field installations, and lessons learned that were required to take this solution from concept to successful performance improvement initiative.

Piloting the 1st Well-Test-Logging in the Middle East, Paving the Way to Low-Cost Dynamic Reservoir Characterization and Well Value Optimization

The development of carbonate reservoirs of a giant field, Offshore Abu Dhabi, requires long horizontal wells to maximize productivity, but at the risk of unwanted gas and water channeling through its inherent heterogeneities. Conformance can be enhanced with dedicated segmented completions (blank sections, Inflow Control Device, Autonomous Inflow Control Device, etc.) or selective acid stimulation (diverter, Limited Entry Liner), which are increasingly implemented to extend well life, and eventually well value. If these technologies have matured, success depends heavily on the quality of the formation knowledge prior to completion. As of today, conventional logs provide the basic ground, but they lack dynamic information, whereas production logging results are obtained too late, when the well is already completed. Initially introduced for the optimization of unconventional well completions (see Jacques et al, URTEC 2019), the Well Testing Logging (WTLog) offers the advantage to record a log of mobility, at the end of drilling the openhole, enabling a favorable timing to influence adapted completion and stimulation design. Contrasted viscosity brines are sequentially circulated through the drill pipes at a constant rate and back-produced from the casing at constant pressure. The fluids interface travels in the drain from the TD to the casing shoe, and the measurement of the differential formation seepage is interpreted into an injectivity profile. Combined with rate fall-off phase analysis, permeability and skin logs are derived. Lasting a few hours and realized with conventional rig equipment (such as cement pumps, coriolis flowmeters, Managed Pressure Drilling system), it is a nonintrusive, safe, and ultimately low-cost operation. Forward, it can replace costly logging, when aimed at characterizing heterogeneities. Within a year, the two first WTLog pilots of the Middle East were successfully designed and carried out. They targeted two appraisal wells in distinct undeveloped reservoirs (Cretaceous and Upper Jurassic formations) which benefited from rich acquisition programs (Image log, Production log) to benchmark and qualify this technology. After an explanation of the technology principles, this paper describes the design, operations, and results of these pilots. It then focuses on the petrophysical consolidation of the matrix/fracture characterization. It concludes by sharing the learnings and offers insight to what extent it is a promising technology to be applied in Middle East carbonate reservoir developments.

How to Block the Water Channels by High-Density Polyethylene Particles Supersaturated Filling Out-of-Screen and Inflow Control Device in Heterogeneous Sandstone Reservoir

At present, the Bohai Oilfield has entered the late stage of high water cut, with a high degree of flooding and an average water cut of more than 80%. Horizontal wells were widely used in tapping the potentials of high water-cut oilfields with avoiding local water flooding, accurately develop enrichment of remaining oil, and improving initial productivity. Until 2020, there are more than 1,200 horizontal wells in the Bohai Oilfield, with daily production accounting for more than 40% of the entire oilfield. However, mainly continental deposits, strong heterogeneity, heavy oil, relatively large mobility ratio, long-term water flooding, and large liquid production have resulted in the obvious dominant channels in the formation, intensified ineffective water circulation, and low oil recovery. The application of horizontal wells faces huge challenges due to the serious water flooding and the prevalence of thief zones. Inflow Control Device (ICD) is becoming more and more prevalent in bottom water reservoirs as it can delay the water breakthrough and significantly improve the economic benefit of a project by producing more oil and less water. The strong microscopic heterogeneity along the horizontal water channeling outside the screen or water channeling along the annulus between the screen and ICD tubular is responsible for the short term even ineffective effect of conventional ICD. Based on the review of the conventional ICD application in the Q oilfield, a workflow is present to design and optimize hybrid ICD to increase the success probability of the validity period of water control.

The Autonomous Inflow Control Valve Design and Evaluation Criteria Along with Well Performance Review for Multiple Installations Across the Globe

Many wells across the globe have been installed with Inflow Control Device (ICD) technology to balance the production across the production interval, addressing some of the challenges associated with horizontal and deviated wells. Nevertheless, ICDs have limitations with restricting unwanted fluids upon breakthrough. Autonomous Inflow Control Valve (AICV) technology functions similar to an ICD initially (i.e., balancing flux across the length of horizontal wells, effectively delaying breakthrough) but provides the additional benefit of shutting off the flow of unwanted fluids upon breakthrough. This paper will present comprehensive AICV completion design workflow along with multiple case histories highlighting the reservoir management benefits of the AICV technology in mitigating un-wanted inflow of water and gas and delivering improved oil production and recovery. Like other AICDs (Autonomous Inflow Control Device), AICV can differentiate the fluid flowing through it via fluid properties such as viscosity and density at reservoir conditions. However, AICV's performance is much more effective due to its advanced design which provides further benefits using both Hagen-Poiseuille's and Bernoulli's principles. AICV technology is based on the difference in the pressure drop in a laminar flow element (LFE) compared to a turbulent flow element (TFE) and has a capability to shut-off the main flow autonomously when an unwanted fluid such as water or gas breakthrough occurs. Thus, reduces well water cut (WC) and/or gas-oil ratio (GOR) significantly. Rigorous single-phase and multiphase flow-loop tests have been conducted covering a wide range of fluid properties to characterize the AICVs flow performance. Extensive plugging testing and accelerated erosion tests have also been conducted. This paper presents some of these flow performance analysis and testing results. Furthermore, the paper will also discuss in detail a reservoir-centric AICV completion modelling and design workflow. Finally, this papers also discuss in detail AICV well performance installed in a light oil as well as in heavy oil reservoirs and how operators achieved higher OPEX saving as well as higher ultimate recovery (UR) from the wells due to prolonged as well as significant reduction in water cut and/or lower GOR. The AICV design methodology and performance evaluation analysis is presented through several case studies. The analysis takes into account the whole cycle: from flow loop testing to characterization, reservoir modelling, optimized AICV completion design and post-installation well performance to evaluate the AICV technology benefits.