Well Automation Based on Flaring

Abstract

At a subsurface level, controlling uneven production and early gas breakthrough are big challenges. It is very difficult to achieve the target production while preventing unnecessary flaring from high gas to oil ratio (GOR) wells. To keep the associated gas within surface compression capacity, the High GOR wells are shut in or partially choked by production programmers through a manual work-process, which doesn't always give optimum results. PDO developed a control solution to ensure produced gas always remains within surface compression capacity while ensuring maximum production. The solution achieves this by continuously monitoring flaring and choking the high GOR wells whenever needed. It does this sequentially from highest to lowest GOR wells choking is done to an optimum level by controlling its flow line pressure above certain target. The concept revolves around automating production programmer's task and optimizing it via continuous monitoring and control in DCS, which allows wells to deliver the full potential up to the surface facility constraints with reduced operator intervention. This novel idea is to integrate subsurface and surface facility Optimization via well control. This was implemented in two of the assets in PDO where frequent flaring was identified. Both facilities have limited compression capacity and number of high GOR wells out of several Gas Oil Gravity Drainage (GOGD) producer wells. In order to achieve the goal of "Zero" flaring, the wells are choked in order from highest to lowest GOR, automatically, up to the optimum limit set by either their respective flow line pressures or to defined lower optimum limit, and optimize the production by opening the wells up to its optimum target, when there is no flare. The similar concept is now being replicated in other assets following a LEAN approach.