Wellsite Geologist Interventions: Successful Horizontal Well Geosteering in Low Resistivity-Low Contrast Reservoirs

Situated off the coast of Peninsula Malaysia, B field has been in production for more than 40 years. Recently, a redevelopment campaign was executed to boost production rates and hydrocarbon recovery by targeting sand thickness less than 6 m TVD through drilling five horizontal wells. This paper, however, will focus on Well 1 and Well 2. Redevelopment of the B field faced several challenges which includes uneven fluid contact due to the gas cap expansion and water intrusion from the prolonged oil production, which was made worse by the different lateral porosity. Structural dip uncertainty and low resistivity contrast further complicated the well placement. Therefore, horizontal well placement through Geosteering was deployed to tackle these challenges. WSG played major role in the horizontal well placement optimization within the pay zone. WSG intervention involved LWD logs observation, gas data and peak trend, cuttings description and oil shows results. As a results of combined efforts from subsurface and wellsite geologist, Well 1 and Well 2 were successfully geosteered despite narrow oil window. Well test results have successfully validated the reservoir productivity of Well 1 with 2358 BOPD with no water production and Well 2 with 2633 BOPD (98% oil & 2% water).