喇嘛甸油田钻井中井径扩大原因分析及对策研究

Cause Analysis and Countermeasures of Well Diameter Enlargement in the Drilling of Lamadian Oilfield

喇嘛甸油田储层埋藏浅、岩性疏松,胶结强度低,在钻井过程中易出现井径扩大问题,给测井曲线解释及油层参数解释带来很大困难,同时影响固井质量。针对此问题,结合地质储层保护和钻井工程等方面的特点及要求,对井径扩大的原因进行分析研究。综合考虑储层地质特征、钻井参数对井径问题的影响,从水力参数和钻井措施等方面,提出了防止井径扩大的井斜预防钻具优选、钻井液参数优选等技术措施。措施实施后井径扩大率由14.8%下降至10.2%。

In Lamadian Oilfield, the reservoir is shallow, the reservoir lithology is loose, and the reservoir cementation strength is low, and therefore the hole diameter easily enlarges in the drilling process, which makes the interpretation of logging curves and reservoir parameters very difficult, and also affects cementing quality. The reasons for the enlargement of hole diameter are analyzed according to the characteristics and requirements of geological reservoir protection and drilling engineering. Some technical measures for pre- venting borehole diameter enlargement, such as optimizing drill string for preventing deviation, optimizing drilling fluid parameters, etc., are put forward by comprehensively considering the effects of the reservoir geologic characteristics and the drilling parameters on borehole diameter enlargement. After the implementation of the measures, the borehole diameter enlargement rate is decreased from 14.8% to 10.2%.