Research and Application of Segmentation Unblocking Technology for Horizontal Well Screen

Abstract

Horizontal well screen completion process has its own advantages, but there are also some problems, in which the screen blockage seriously affects its efficacy. However, due to various factors (such as heavy components in crude oil plugging the sand filter), the implementation of conventional pickling and sand washing operations is not ideal. In response to this problem, this paper proposes a new unblocking technology - segmentation unblocking technology for horizontal well screen. Firstly, on the basis of studying principle of the technology, optimization of water jet method and hydraulic sanding nozzle, nitrogen foam water jet experiment and water jet construction displacement experiment are carried out for horizontal well screen, which laying the foundation for application of segmentation unblocking technology. Further, horizontal well screen segmentation unblocking experiment and oilfield application are carried out. Optimization results of water jet method show that, For large displacement construction with still wellhead, whole section construction selects type of inlet liquid through annulus between oil pipe and casing pipe and outlet liquid through oil pipe. For small displacement construction with frequent dynamic wellhead, segmentation construction selects type of inlet liquid through oil pipe and outlet liquid through annulus between oil pipe and casing pipe. Optimization results of hydraulic sanding nozzle show that Streamlined nozzle is better than nozzle with iso variable. Experiment results of horizontal well screen segmentation unblocking show that, segmentation unblocking technology can effectively improve productivity of horizontal well and oilfield application achieved good results. Five wells were shut-in, periodic shut-in or low production before segmentation unblocking. After segmentation unblocking, daily oil increment can reach 23.57 t, and interval cumulative oil increment can reach 4756 t.