非常规油气水平井湿鞋固井首段压裂新工艺

A new first-stage fracturing process of horizontal well in unconventional oil and gas based on wetshoe cementing

刘东亮 陈玉平 李傲仙 郭莉

LIU Dongliang CHEN Yuping LI Aoxian GUO Li

中化石油勘探开发有限公司

Sinochem Petroleum Exploration & Production Co., Ltd., Beijing 100031, China

国内非常规油气水平井分段压裂工艺首段压裂时一般采用连续油管射孔、爬行器输送射孔和趾端滑套打压3种方法来建立井筒与地层的连通，这3种方法虽然基本满足了国内目前井深条件下首段压裂改造需求，但是存在工序复杂、效率低、操作成本高、施工风险大等问题，为此，提出了一种新型首段压裂工艺。该工艺充分利用湿鞋固井(WETSHOE)技术特点，通过高性能浮箍、浮鞋和特制胶塞等固井工具实现井眼底部不留水泥，在保证井筒安全的前提下建立管鞋与地层的连通，首段压裂即可采用“泵送”桥塞和射孔枪，从而实现全井段“泵送”的一致性，提高了压裂施工效率，降低了成本。该技术在北美非常规油气田广泛应用，单井可节约成本约30万美元，首段压裂成功率提高到98%以上，压裂效率显著提升。

In China, coiled tubing perforating, crawling device transmission perforating and toe sliding sleeve pressurization are generally adopted to establish the connection between wellbore and reservoir during the first-stage fracturing of horizontal-well staged fracturing of unconventional oil and gas. These three methods can basically meet the needs of the first-stage fracturing stimulation under the domestic current well depth conditions, but they have the problems of complex process, low efficiency, high operation cost and great construction risk. To this end, this paper put forward a new kind of first-stage fracturing process, which makes full use of the technical characteristics of wetshoe cementing. Through this process, no cement is left at the bottom of the hole by using the cementing tools such as high-performance float collar, float shoe and tailored rubber plug, and the connection between pipe shoe and reservoir is established while the wellbore safety is guaranteed, so that bridge plug and perforating gun can be pumped during the first-stage fracturing. Thus, consistent pumping in the whole borehole is realized, the fracturing construction efficiency is improve, and the costs are reduced. This process is widely applied in the unconventional oil and gas fields of the North America, which saves single-well cost by 300 thousand dollars, increases the success rate of first-stage fracturing up to over 98%, and improves the fracturing efficiency significantly.

10.13639/j.odpt.2023.01.011