Innovative Strategies and Key Considerations for Developing a Multi-Layered Low Permeability Porcellanite Oil Reservoir: A Case Study of ABH Field, India
Authors: Singh Ranjeet , Agarwal Prashant , Gupta Sumit , Kothiyal Manish Dutt , Kumar Vineet , Gupta Abhishek Kr. , Kumar M. Suresh 
Published: November 2024

Development of multi-layered tight oil reservoirs has been challenging due to relatively lower per-well oil recovery and higher per-barrel costs. Significant uncertainty exists in predicting the long-term productivity of the wells. Therefore, a robust understanding of reservoir quality, geomechanical properties and the selection of optimal well designs is crucial. This paper showcases innovative approaches and strategies adopted in the development of one such low-permeability porcellanite oil reservoir.

The Aishwariya Barmer Hill (ABH) is a low-permeability (approximately 1 md), and high-porosity (average 25%) oil reservoir located in the Barmer Basin, India. This field is characterized by multiple reservoir layers and fault blocks and has been developed with more than 50 horizontal wells, ranging in total length up to 2800 mMD (lateral lengths up to 1300m) and employing 10-18 stages of hydraulic fracturing. A seven-well appraisal campaign was executed utilizing regional understanding, fluid and reservoir properties. Various well types (vertical/horizontal, longitudinal/transverse, open hole/cased hole), hydraulic fracturing strategies (swell packer with sleeves/plug and perf) and artificial lift compatibilities (jet pumps/rod pumps) were tested. Fluid sampling and coring were also conducted. Detailed geomechanical tests were performed on the core, and a 1D geomechanical model was prepared incorporating image logs, microseismic data and other relevant information.

Information acquired during the appraisal campaign, such as in-situ stress direction, natural fracture density, and stress contrast, aided in determining well density and orientation. Horizontal wells proved to be three times more productive compared to vertical wells. Production logging in horizontal wells established contributions from the long horizontal section, aiding in determining the optimal length of the horizontal section for subsequent wells. Insights gained from the appraisal campaign were crucial in conceptualizing the first full-field development campaign comprising 39 wells (37 horizontal and 2 deviated). Wells were proactively geo-steered into the targeted reservoir, and frac sleeves were used for coil tubing-assisted precise hydraulic fracturing, offering flexibility for reservoir management purposes. Production behaviour of these 39 wells contributed to further refinement of field understanding concerning hydraulic fracture design, region-wise PVT understanding and modification of artificial lift design. A water flood pilot was also conducted to assess future water flood potential.

The field reached to a peak oil production of 10,000 bopd with approximately 15 mmstb of oil already recovered till June-2024. Leveraging lessons learned from the previous campaign, two additional infill campaigns of five and fourteen wells have been undertaken and a third campaign involving water flooding is under planning. This paper elucidates the key considerations and various steps taken during the five-plus years of development journey and its outcomes. The insights gained from the ABH development can be utilized to delineate the impact of various parameters on field performance and can facilitate the fast-track development of similar reservoirs.