保德煤层气田黄河压覆区长水平段水平井钻井完井技术

Drilling and Completion Technology of Horizontal Wells with Long Horizontal Section in the Yellow River Overlay Area of the Baode Coalbed Methane Field

保德煤层气田北部优质煤层气藏开发受到城市、黄河压覆等地面复杂情况影响,为了实现有效动用,分析了该地区煤层的地质特点,考虑煤层倾角、垂深和常规钻井工艺等因素,开展了井身结构优化、井眼轨迹控制、钻井液优选及完井工艺优化研究,形成了集约化大平台水平井钻井完井技术。通过集成应用新技术,实现了地表复杂地区煤层气优质储量的经济开采。在煤层垂深800.00~1000.00 m、上倾角度2°~5°条件下,水平段极限长度可达到1700.00~2000.00 m。在此基础上,研发了玻璃钢筛管完井系统,实现了水平井完井井筒“可重入、可作业、可维护”的功能,满足了采煤采气一体化要求,现场试验取得了较好的开发效果。长水平段水平井钻井完井技术为保德煤层气田黄河压覆区煤层气的开发提供了技术支持。

The high-quality coalbed methane reservoir in the northern part of the Baode coalbed methane field was affected during its development by complex surface conditions including overlays of city and the Yellow River.The in-depth analysis and evaluation of geological characteristics of coal seams in the city and the Yellow River overlay area were carried out,taking into consideration of coal seam dip angles,vertical depth,and conventional drilling technology,so as to effectively exploit the gas reservoir.The optimized design for drilling and completion of intensive horizontal wells has been done through casing program upgrading,well trajectory control,optimization of drilling fluid system and completion technology.By means of the integration of new technologies,the economic production of high-quality CBM reserves in complex surface areas was realized.The ultimate horizontal section length can reach 1700–2000 m in coal seams at a vertical depth of 800–1000 m with an upward inclination angle of 2°–5°.The developed completion system with FRP screen pipe can realize the function of re-entry,operation,and maintenance of the horizontal well,meet the requirement of coal mining and gas production integration.The field test has achieved good development results.The drilling and completion technology of horizontal well with a long horizontal section provides a new way for the exploitation of CBM in the Yellow River overlay area of the Baode Coalbed Methane Field.