Pushing the Limits in Deep Water Data Acquisition for Accelerated Field Development: Industry Record Batch Well Testing

Abstract

Abstract This paper presents a dynamic deepwater well testing solution that was developed to execute consecutive well tests on multiple reservoirs of various parameters and complexities and describes the design, planning, application, and benefits of the batch well testing package. Batch well testing has the potential to optimize well testing operations, improve equipment utilization, reduce operator costs, and obtain significant amounts of dynamic reservoir data quickly for field development and facility design. Esso Exploration and Production Guyana Limited (EEPGL), ExxonMobil's Guyana affiliate, and its co-venturers had a challenging objective to complete several deepwater development projects at an accelerated pace in the Stabroek block of Guyana, which required the acquisition of an extensive amount of dynamic reservoir data and representative fluid samples. The data and reservoir samples were required to inform creation of field development plans and to drive a fit-for-purpose floating, production, storage, and offloading vessel (FPSO) and topside designs. This led to an extensive well test program utilizing existing predrilled appraisal wells that were conditioned and prepared for well testing. This was enhanced by a dedicated drillship equipped with a surface well test package to test all commercial discoveries consecutively. Extensive laboratory tests were performed on reservoir samples collected during wireline sampling to help determine operating parameters for each well test and identify mitigation measures to be employed, alleviating potential flow assurance risks such as wax deposition, asphaltene breakout, and hydrates. The reservoir fluid studies conducted on the wireline samples also helped to create specific fluid identifications for the multiphase meter to increase accuracy of flow rates and fluid composition during well testing. The surface well testing package installed on the rig was optimized to efficiently process a range of fluid types form high gas-oil ratio oil to black oil wells with high flow rates. Testing multiple deepwater wells successively involved precise planning and a robust maintenance plan between wells. A dedicated rig for batch well testing resulted in significant cost synergies for the operator, enabled precise planning, streamlined onshore and offshore maintenance, and assisted supply chain management to ensure equipment availability and performance reliability for the continuous program. This paper highlights the industry record implementation of a batch well testing program, an industry first in this operating environment, that was designed to be executed for seven wells and that enabled the delivery of high-quality reservoir data from multiple differentiated deepwater reservoirs quickly in support of the operator's potential growth plans. The program was completed with zero spills to the environment.