Production testing of wells in Bahrain field historically was carried out at Well Manifolds using 2-phase test separators, mechanical liquid meter and gas chart recorder. Flow line liquid samples were collected for water cut measurement. Production fluid was diverted to test separators using manually operated valves on production and test headers. When Tatweer Petroleum took over operation of Bahrain field in late 2009, there was a need for more well testing to improve surveillance of wells performance and accommodate new wells added through aggressive drilling program. This was possible through contracting well testing services to assist in handling the increased number of well tests and also validate tests of the company owned Test Separators.
In 2012, 3-phase test separators were introduced as replacements to the old, undersized 2-phase test separators. The new separators are equipped with oil, water and gas meters, and automatic level and pressure controls. When the new testers were first introduced, they did not perform well and only one third of the tests were validated as “good” by Production Engineers. A multi-disciplinary team was set up and tasked with developing a work plan to solve problems with the new test separators in order to improve validation of well tests. The team addressed several issues including chemical injection, instrumentation, automation of well testing process, capture test data into software applications, trouble shoot wells, develop KPIs, and train operators.
As a result of the team's effort, well testing performance has significantly improved. Well test validation has increased from 30% to 90% and the number of daily well tests doubled from 32 to 64. With this improvement, the company was able to reduce the contracted well testing service and reduce cost. Additionally, through quality well testing, there was an improved understanding of individual wells performance, thus allowing better production optimization and reservoir management.