Title

New cementing technology of dynamic pressure-control for high-pressure gas wells
and its application

作者

曾凡坤聂世均

单位

中国石油川庆钻探工程有限公司井下作业公司，四川成都 610052

Organization

CCDC Downhole Service Company, CNPC, Chengdu 610052, China

摘要

随着川西勘探开发向盆周拓展，勘探对象以深部下二叠统、寒武系为主。川西复杂超深井油层尾管固井深度在7 500 m左右，普遍面临纵向上多压力系统、窄安全密度窗口特点，常规尾管固井工艺已不能满足上述井况下环空有效封固。为解决该区块超深井尾管固井漏喷同存难题，针对压力敏感地层开展了动态控压固井技术研究，形成以窄密度窗口固井环空压力控制和防窜水泥浆体系为核心的固井配套工艺，2017年,川庆钻探公司在中石油四川盆地LG70井ф114.3 mm控压尾管固井作业中首获成功，有效确保了小间隙、井温高、漏喷同层等复杂井况下的封固质量，并在后续九龙山、双鱼石等构造上超深井固井作业中推广应用，取得良好效果，为窄密度窗口井筒条件下防窜、漏提供了一种切实可行的固井工艺。

Abstract

With the exploration and development towards the periphery of the basin, exploration object is focused on the Permian and Cambrian in deep formation of Western Sichuan. Reservoir liner cementation depth has reached 7,500 meters under these circumstances. Cementing of ultra deep well in this exploratory area is generally faced with multiple pressure system and narrow density window, so conventional cementing process has not already met the requirement of effective sealing in view of the above-mentioned facts. Loss circulation and well kick co-existing are great challenges for liner cementing. For pressure-sensitive stratum, we have conducted dynamic pressure control cementing practice, forming cementing accessory process to be cored on annular pressure control under narrow density window and anti-channeling cement slurry. Pressure-control liner cementing process has successfully applied to 114.3 mm liner job in LG70 as the deepest exploratory well in Sichuan Basin for the first time in 2017. This technological skill has ensured the sealing quality effectively under the condition of narrow annular gap, high temperature, loss circulation and gas cut coexistence. Series of generalization and application have been made successfully for the cementing of ultra deep well in geological structures of Jiulongshan, Shuangyushi, etc. This also has provided a new practical cementing technology for leak prevention and anti-gas channeling of follow-up ultra deep gas well.

关键词：

动态控压; 漏喷同存; 防窜水泥浆; 实时监测

;

Keywords:

dynamic pressure-control; loss circulation and gas cut coexistence; anti-channeling slurry; real-time monitoring

;

基金项目

DOI

10.6056/dkyqt201803024

高压气井动态控压固井新技术及应用