牛东区块无固相甲酸盐钻井液体系的应用

Application of clay free formate drilling fluid in East Niujuanhu Block

盛子堂 余丽彬 周显东 曹德荣

中原石油勘探局钻井三公司，河南 濮阳 457001 西部钻探工程公司吐哈钻井工艺研究院，新疆 鄯善 838202

No.3 Drilling Company, Zhongyuan Petroleum Exploration Bureau, SINOPEC, Puyang 457001, China Tuha Well Drilling Technology Research Institute, West Drilling and Exploration Enginnering Co. Ltd., CNPC, Shanshan 838202, China

针对牛东区块油藏压力低、微裂缝发育、储层水敏性强等特点，优选了满足该区块钻井施工及油层保护要求的低密度无固相甲酸盐钻井液体系，在现场40余口井的应用中，有效减少了钻井液漏失，提高了机械钻速，并较好地保护了油层。无固相甲酸盐钻井液体系与聚磺钻井液相比，机械钻速提高了16.5%，单井漏失量减少了52.8%，油层保护效果好，投产初期产液量提高了20.9%。无固相甲酸盐钻井液密度低，抑制性好，对油层伤害小，可以有效减少低压油藏钻井过程中的漏失及保护油气层。

According to the characteristics of low pressure and rich in tiny fractures and high water sensitivity in reservoirs of East Niujuanhu Block, clay free and low density formate drilling fluid is optimally selected to meet the requirements for drilling and reservoir protection. The fluid has been used in more than 40 wells, and it can decrease the leakage of fluid effectively, raise the penetration rate and protect the reservoirs. Compared to polysulfonate fluid, penetration rate is increased 16.5 percent, volume leak per single well decreases 52.8 percent. With good reservoir protection results, early production liquid production has been increased
20.9% . The clay free drilling fluid , which has the features of low density, better suppression, and small damage to reservoir, can be used to effectively reduce fluid loss in reservoirs with low pressure and to protect oil and gas layers.