Success Factors for Reservoir Navigation in the Niger Delta Sedimentary Basin: A Case Study of Well-X

Day 2 Tue, August 01, 2017

Okowi

Foekema

et al. 2017

Variable reservoir thickness, heterogeneity, and presence of geological truncations are some of the challenges inherent in draining complex reservoirs. These challenges affect the depth of detection of some formation evaluation tools, the ability to optimally place the well in the target horizon, and the ability to remain in the sweet spot throughout the drain length. To mitigate these challenges, reservoir navigation service with fit-for-purpose tools and robust software is required. This paper is a case study of the application of the VisiTrak™ tool and Multi-Component-While-Drilling (MCWD) inversion software (Sviridov et. Al., 2014) in the geosteering of Well-X. VisiTrak is an extra deep-reading azimuthal propagation resistivity tool. MCWD is software that essentially creates a geological earth model from the readings of azimuthal propagation tools. It is multi-layer inversion software. Well-X is located in offshore Niger Delta and the target reservoir consists of several individual turbidite complexes and stacked channels. The successes recorded in this geosteering case include accurate subsurface structural interpretation, reservoir characterization, and achieving well objective in terms of net sand drilled. This paper demonstrates the importance of reservoir navigation in accurate well placement, the benefits fit-for-purpose tools bring to geosteering complex reservoirs in the Niger Delta and shows the value of data integration in reservoir navigation service.

The Use of Reservoir Navigation Service RNS with VisiTrak Geospatial Navigation and MCWD Inversion Analysis Service in Nigeria on a Deepwater Project: Geosteering in Thin, Faulted, and Heterogeneous Reservoir

Day 2 Tue, August 01, 2017

Okowi

Foekema

et al. 2017

Reservoir Navigation in Njaba Field – Challenges, Procedure and Results

Day 3 Wed, August 07, 2019

Amadi

Toyobo

et al. 2019

Due to the low oil price, Exploration and Production (E&P) companies are driven to reduce the cost per barrel of oil equivalent (BOE). The application of reservoir navigation services, in the placement of high angle and horizontal (HAHZ) wells in the sweet spot of reservoirs, has aided in meeting this economic need of the E&P, while also improving hydrocarbon recovery. Reservoir navigation services (RNS) can be regarded as another tool for improving the odds of success while drilling of HAHZ wells. This service involves the integration of real-time data (deep-reading azimuthal resistivity, gamma-ray, density image, resistivity image logs, near bit inclination and a fit for purpose rotary steerable system) to accurately position the well-bore relative to specific subsurface targets, while remaining within the constraints of the drilling and completion program. RNS also require a software package capable of pre-well modeling, displaying the acquired real-time data and interactively adapting the model to the real-time data. Geosteering in Njaba field involved a comprehensive pre-well planning, discussions, documentation and management approved decision-tree. Using three wells for this study, this paper describes the challenges, procedures and results of geosteering in Njaba Field located on-shore Niger-Delta. From different entry points, wells NJX1, NJX2, and NJX3 were planned to drain the same reservoir and optimize hydrocarbon recovery within the reservoir. Some of the challenges encountered includes geosteering the wellbore above a pre-determined production TVD hardline while simultaneously avoiding drilling into an overlying undulating shale cap rock, vertical seismic uncertainty and undulating formation boundaries.

Advances in the Quantitative Geological Evaluation of Development Wells in Challenging Geological Targets

Austin

Wang

Day 2 Wed, June 09, 2021

et al. 2021

Reservoir navigation is a common and integrated part of the drilling process to steer wells very precisely. It is a requirement for many of today's complex deviated and horizontal development wells steered through challenging and small geological targets that can be as small as two metres in size. The capability is a key enabler for the oil industry and has contributed significantly to the prolongation of the economic well being of most oil producing provinces around the world. In order to be successful, reservoir navigation must combine advanced downhole logging while drilling (LWD) tools, telemetry of LWD data to surface in real-time, the ability to steer while drilling, fit-for purpose software applications and perhaps most important of all, skilled personnel. That said, it is currently common practice for reservoir navigation to be performed with a dataset that is restricted to a vertical ‘curtain’ section derived from the development well. This is an unnecessary restriction that is often self imposed because of the limitations of the software applications being employed. With improving computer power, it can and should be superceded in favour of a more holistic approach. The new reservoir navigation analytical processes are all designed to be performed at speed and in real-time while drilling the reservoir, on demand, at any stage, within minutes. These enhancements quantitatively illuminate the critical financial consequences of a well's geological drilling results. These are usually greater than the economic benefits of more efficient well operations. It means well owners can now operate in an information rich environment leading to better multi-disciplined team work and improved operational decision making. The benefit is better wells that produce more hydrocarbons at lower cost. A real data set comparing a pre-well 3D model with realistic real-time geological updates and visualisations in three dimensions demonstrates the validity of the method. The pre-well and real-time 3D models can also be utilized to generate quantitative volumetrics calculations while drilling. The workflows provide an information rich environment for operational decision making leading to better wells.