东海某井压差卡钻原因分析及处理措施

Cause Analysis and Treatment Measures of Differential Pressure Sticking in a Well in the East China Sea

姜小龙 袁修锦 陈刚 孙乾坤

JIANG Xiaolong YUAN Xiujin CHEN Gang SUN Qiankun

中海油能源发展股份有限公司上海工程技术分公司, 上海 200335

Shanghai Engineering Technology Branch, Energy Technology & Services Co., CNOOC, ShangHai 200335, China

东海油气田高压低渗特点突出，钻井液密度过低不利于井控安全，而钻井液密度过高又会导致较高的压差，诱发压差卡钻、卡电缆等工程事故。此文从井身结构、地层压力、钻井液密度、井眼轨迹等方面探究东海某井φ215.9 mm井段压差卡钻发生的原因，简述解卡处理过程，进而针对高压低渗地层的钻井施工以及压差卡钻的预防和处理提出合理化建议，可以为东海同类地层的钻井施工以及有效避免和解除压差卡钻提供参考。

The high-pressure and low-permeability characteristics are prominent in the oil and gas fields of the East China Sea.The lower density of drilling fluid is not conducive to well control safety. However, the higher density of drilling fluid will lead to high pressure difference and induce engineering accidents such as pressure differential sticking of pipe and cable. This paper explores the causes of the pressure differential sticking in the φ215.9 mm well section in the East China Sea from the well structure, the formation pressure,the density of drilling fluid,the borehole trajectory,etc., then briefly describes the unfreezing processes,eventually put forward some valuable suggestions for drilling operation in high-pressure and low-permeability formations and for preventing and treating differential pressure sticking. It can provide a reference for drilling in the same formation in the East China Sea and effectively avoiding or relieving the pressure differential sticking.

https://doi.org/10.3969/j.issn.1008-2336.2018.03.070