乍得H区块Baobab N-8井防塌钻井液技术

Anti-sloughing drilling fluid technology for Well Baobab N-8 in Block H of Chad

张洁 钱殿存 杨海军 黄宏军 郭彬 王玺

中国石油钻井工程技术研究院，北京 100083

Research Institute of Drilling Engineering and Technology, CNPC, Beijing 100083, China

在勘探开发过程中，乍得H区块下部地层存在严重的井壁失稳问题。利用X射线衍射、阳离子交换容量等试验手段，对Baobab N-8井岩样进行了系统分析，探讨了该地区复杂地层的井壁失稳机理。通过大量的单剂优选和配方优化试验，优化出适合乍得H区块下部地层特性并符合环保要求的防塌钻井液体系。研究结果表明，该体系可抗120 ℃高温，抗岩屑污染达到10%，抗钙污染达到1%，抗NaCl污染达到10%，可满足乍得H区块易坍塌地层钻井的需要。

In the process of exploration and development, some wellbore instability problems have been encountered in the lower formation in Block H of Chad. The physical-chemical properties of rock samples from Well Baobab N-8 in Block H were analyzed using the experimental methods of X-ray diffraction and cation exchange capacity. The wellbore instability mechanism of complex reservoir in this area was discussed. A new anti-sloughing drilling fluid suitable to Block H in Chad was developed by selecting all kinds of additives and optimizing formulation. The results show that the system can resist the high temperature of 120 ℃, the calcium tolerance is 1%, the salt tolerance is 10% and the drilling cuttings tolerance is 10%, which can meet the requirement of drilling in in this area.

10.6056/dkyqt201206034