延长天然气探井钻井液体系优化研究

Optimization of drilling fluid of natural gas exploration wells in Yanchang Oilfield

延长油田天然气勘探处于起步阶段,在钻井过程中遇到井漏、井壁垮塌、井眼扩大等问题,严重影响了钻井质量及钻井进度。对天然气探井现场使用的钻井液体系进行了性能评价,结果表明,清水聚合物钻井液和三磺钻井液抑制性能、失水造壁性能、封堵能力都较差,不能满足现场安全、高效钻井的要求。并在此基础上优化出了新的钻井液配方,性能评价结果表明,优化后的钻井液体系流变性能良好,抑制性能、失水造壁性能佳,能够解决地层漏失、垮塌等钻井问题。

Because natural gas exploration of Yanchang is at the starting stage, it encounters many problems of well drilling, such as well leakage, borhole collapse, hole enlargement, etc, which influence drilling quality and speed seriously. The paper was evaluated performance of present and optimized drilling fluids in laboratory. The results showed that inhibition performance ,filtration performance and plugging capacity of present drilling fluids were so poor that it cannot meet the technical requirements. According to the results, new formulas of drilling fluids had been optimized on purpose. And their theological performance, inhibition performance and filtration performance were good and the optimized drilling fluids can solve problems of well leakage and borehole collapse during drilling gas exploration wells in Yanchang Oilfield.