衬管完井水平井新型布酸技术研究与应用——以安岳气田磨溪构造龙王庙组气藏为例

Research and practice of new acid arrangement technology in horizontal well with liner slot completion

衬管完井具有泄流面积大、完井成本低等优势,目前成为水平井完井的主要方式之一。衬管完井水平井酸化改造的关键是如何实现水平井段上的均匀布酸,但由于割缝衬管与岩石壁面之间环形空间未真正封隔,常规分段工艺的应用受到限制,致使衬管完井水平井均匀布酸困难。为此,通过理论研究和室内实验评价,形成了衬管完井水平井新型均匀布酸技术:(1)预测水平井段上初始表皮系数分布剖面,明确不同井段损害分布特征;(2)建立水平井段上酸液流量数学模型,模拟计算不同井段暂堵转向净压力值;(3)优化设计不同井段衬管割缝参数,优选转向剂加量,实现井底不同转向净压力;(4)采用数值刻画方法定量表征酸蚀蚓孔形态,优选适合的酸液体系。在安岳气田现场应用8口井,井均增产倍比达1.95,井均增加测试产量67.3×104 m3/d,相比射孔完井,单井节约完井成本900万元,对同类型气藏衬管完井水平井均匀布酸技术具有借鉴意义。

Liner slot completion is one of the main horizontal well completion types, which has remarkable advantages,such as huge discharge area,and low cost.Uniform acid arrangement is the key to stimulation of horizontal well with liner slot completion. It is hard to implement acid arrangement in horizontal well with liner slot completion,through the annulus space between liner slot and wellbore is not sealed successfully,routine sectional stimulation technologies are limited.A new acid arrangement technology in horizontal well with liner slot completion was generated, via theoretical and experimental research. It can define formation damage characteristics of different well intervals through predicting initial skin factor profile of horizontal well intervals.Mathematical model of acid flowing in horizontal well was established,and diver- sion pressure of different intervals was simulated.Optimizing the liner cutting parameters, and different diversion pressures were obtained by changing quantity of diversion dosage. The acid wormhole shape was characterized by numerical method,which is able to optimize acid system.It was applied to 8 wells in Anyue Gasfield.The average of stimulation multiple proportion was 1.95 ,and the average testing production of individual well increased about 67.3 × 10^4 m^3/d, compared with perforation completion, single well completion saving cost 9 million yuan. Therefore, the economic benefit is remarkable, which serves as a reference for other gas reservoir.