Breaking of paradigm: gas-oil-contact (GOC) water injection

Abstract

The conventional way to produce an oil reservoir that has a gas cap is to produce only from the oil column while keeping the gas cap in place so that gas cap expansion could supplement additional energy to the reservoir. When a reservoir has a large gas cap, gas can either cone down to the oil producers or breakthrough as a front, leading to substantial increase in the gas-oil-ratios at the oil producer. In Malaysia, the associated gas are either re-injected back into the reservoirs or diverted for sales. Flaring, in principle, is not allowed. Unfortunately, there are some cases where the associated gas in uneconomic for sales due to its contaminant, therefore, flaring limit will be imposed, for example, Dulang oilfield best-preferred solution is to keep the contaminant gas in place to minimize environmental impact