Economic Evaluation On Adjustment Of Old Area In Zhongyuan Oil Field

Zhongyuan oilfield has been put into exploration and development for more than twenty years. Due to the long development period, all kinds of surface and subsurface facilities have seriously become old. Especially in recent thirteen years of high-speed progressive development, the main fault blocks have come into three-high development stage. Because the faults are more and fault blocks are small with complicated structure and reservoir and a narrow oil-bearing ribbon, it is very difficult to control the reservoir by primary well pattern. At the same time, some oil and water wells are abandoned or stopped production because of the engineering or geology factors such as casing failure, interval abandonment and high water cut. Casing failure is increasing and the casing string is not replaced in time. Water quality of injector is low and the replacement and maintenance on the surface system equipment and technology process flow are far behind which results in the secondary incomplete of injection and production system and the poor stable production.In recent years, the technologies as drilling adjustment well, casing withdrawal sidetracking, open- window sidetracking,four-inch casing and replaced casing , workover and squeezing off have been formed to adjust and cure in maturing area of Zhongyuan oilfield. Entrusted by Development Department, a set of analysis methods and matching softwares have been developed aimed at the development characteristics. After applied and checked in practice, it is shown that this system tallies with the features of exploration and development industry and is feasible in theory, practice and operation.