Low-flow lift solution developed for extended-reach laterals

摘要

A novel artificial lift solution promises reliable production for marginal wells while preventing potential gas-locking problems. To counter dwindling reservoir pressures and maintain production at economic levels, many wells will eventually have to go on some form of artificial lift. And while downhole pumps such as sucker rod pumps and electrical submersible pumps (ESPs) have been widely used to successfully bring oil to surface from low-pressure wells, they share a common challenge in the form of produced gas. High gas volumes entrained in the fluid prevent the use of conventional pumping equipment and require a solution to handle or avoid free gas entrained in the fluid from being produced. As liquid rates fall and gas production rises in a well (a process that may take only a few months to a few years), these pumps reach a limit on reliable operation. In horizontal wells, for example, the accumulation of gas and water in the low spots of the lateral predispose the well to sluglike production cycles characterized by an alternating flow of gas and liquid. Gas slugs can cause erratic liquid loading, which may cause the pump to cycle on and off. Under such conditions, gas separators and tapered pumps, which are typically used to prevent gas locking, are rendered ineffective.