查干凹陷火山岩与泥岩地层安全钻井影响因素分析

External Market Management Committee, Zhongyuan Petroleum Engineering Co. Ltd., SINOPEC, Puyang 457001, China Research Institute of Drilling Engineering and Technology, Zhongyuan Petroleum Engineering Co. Ltd., SINOPEC, Puyang 457001, China No.3 Drilling Company, Zhongyuan Petroleum Engineering Co. Ltd., SINOPEC, Puyang 457001, China Geophysical Wireline Logging Company, Zhongyuan Petroleum Engineering Co. Ltd., SINOPEC, Puyang 457001, China

中原油田内蒙探区查干凹陷火山岩地层发育，同一裸眼段含有大段玄武岩、凝灰岩、泥岩与砂岩互层，地质条件变化大且难以预测，在钻井过程中易出现井壁垮塌、缩径、卡钻、井斜等复杂情况，严重影响安全钻井。针对这些施工难点，根据“预防+巩固”的井壁稳定思路，从钻井液类型、密度、流变性以及钻进方式、钻压、轨迹控制和现场操作等方面着手，开展了火山岩与泥岩地层安全钻井影响因素分析和现场应用，提出了针对性的技术措施，取得了明显成效。2口应用井较对比井钻井液密度降低0.1 g/cm3以上，钻井周期缩短20%以上，井径扩大率降低50%以上，实现了查干凹陷深探井安全钻进。

The volcanic formations develop in Chagan Depression of Inner Mongolia exploration area operated by Zhongyuan Oilfield. There are thick basalts, tuffs and mudstone and sandstone interbedding in the same open hole section. Geology condition is difficult to be predicted. In the process of drilling, the down hole complex situations such as wall collapse, hole shrinkage, sticking accidents and hole deviation easily occur, which seriously affects safe drilling. Aimed at these difficulties, based on the thought of prevention and consolidation and from several parts of drilling fluid type, density, viscosity and drilling method, weight on bit, trajectory control and field operation, this paper analyzed the influence factor of safe drilling for volcanic rock and mudstone formation and put forward the corresponding technical measures, getting a obvious effect. Compared with the correlation wells, the drilling fluid density of two applying wells reduced by more than 0.1 g/cm3, the drilling cycle shortened by more than 20% and the hole enlargement ratio decreased by more than 50%, achieving the safe drilling of deep exploring wells in Chagan Depression.

10.6056/dkyqt201306035