Horizontal wells are susceptible to early water breakthrough (EWBT) due to reservoir heterogeneity and "the heel-toe effect", caused by frictional pressure losses along the well that lead to a non-uniform production profile. Also, with heavy oil reservoirs, early water breakthrough can occur because of viscous fingering due to an unfavorable mobility ratio caused by a difference in the viscosity of heavy oil and water. This ratio leads to a high inflow of water into the wellbore. EWBT is undesirable as it brings with it negative implications; from low oil productivity to corrosion in the wellbore and water disposal challenges. There are different industry solutions to managing early water breakthrough including reservoir based improved oil recovery (IOR) or enhanced oil recovery (EOR) methods such as thermal EOR (steam flooding, cyclic steam injection), chemical EOR (polymer or alkaline flooding) or miscible EOR (with methane or ethane to reduce capillary resistance). These methods are however complex and broad field-based applications with varying experiences in the outcomes of the field implementation. There are also mechanical well specific solutions for mitigating EWBT and in this paper, we present the considerations and plans for the application of Autonomous Inflow Control Devices (AICDs) for the mitigation of EWBT in the Niger Delta. AICDs are relatively new and are known for autonomous selective choking of fluid phases. They restrict the flow of less viscous phases like water while allowing more viscous phases like heavy oil to pass through, with minimum pressure drop. The paper examines the different causes of EWBT in Ogini field and the different solution options available. It presents the cost/benefit analysis and modeling considerations resulting in the selection of AICDs for EWBT mitigation. The paper concludes with the technology implementation plan developed for its successful deployment in the upcoming drilling campaign.

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Near wellbore impairment result from various factors such as mud invasion, filter cake deposition, and fines migration in producing fields. Micro Emulsion Chemistry, other than the traditional acid stimulation presents a new and novel remedial treatment for near wellbore impairment. A microemulsion is a typical Newtonian fluid system distinguished from emulsions owing to its being stable thermodynamically and self-organizing. This technical paper explains the process of candidate selection, data gathering, job execution, and resultant crude oil gain from deploying micro-emulsion technology (MET) on some strings in the Ogini and Isoko fields. The fields have different and unique challenges. While the Ogini field has characteristic heavy oil and viscous crude, the Isoko field has wax deposition challenges. Deploying MET treatment in both fields yielded record-breaking results and productivity (PI) improvements in multiple folds. A total of 3,500 bopd (incremental oil) was achieved from treatment on four strings in both fields.

Oil Mining Lease 26 (OML 26) is held by NNPC and First Hydrocarbon Nigeria Limited (FHN) in a Joint Venture relationship and operated by an Asset Management Team (AMT). The license consists of several oil and gas discoveries including the Ogini, Isoko, and Ozoro fields on the western part, Ovo in the central area and Aboh to the east. Oil Production is mainly from the Ogini and Isoko fields with the Ogini field contributing the largest volume. The Ogini oil is relatively heavy, with in-situ oil viscosity ranging from 3 to 59cp, and an oil gravity ranging from 15°API to 19°API. Field development and production from the Ogini field has been very challenging with the characteristic low GOR, low rate and high watercut. Oil production peaked at 8,900 stb/d shortly after field start-up in the 80s and has been declining since then. In 2018 however, the field witnessed breakthrough performance stemming from production optimization initiatives and strategies which unlocked resource potential of the field. A peak production of ca 17,000 bopd was recorded during Q4 of 2018 without drilling new wells. A number of production enhancement activities carefully designed, planned, and executed coupled with change in operations philosophy released more volumes transforming the production levels and production profile of the field from a mere 3,000bopd to ca 17,000 bopd peak production. This paper highlights the strategies, optimization techniques and the paradigm shift in operational culture that resulted in the significant change and ramp up of production in the field.