摘要
油基钻井液是页岩气开发常用的钻井液体系,但存在污染大、费用高等问题,通过改进水基钻井液体系开发页岩气藏可以有效地解决上述问题。对川西须家河组五段泥页岩的工程地质特征进行分析发现,该层属硬脆性泥页岩,膨胀性矿物体积分数低,微裂缝发育,井壁失稳是影响水基钻井液使用的主要因素。通过室内实验优选了抑制剂、封堵剂和降失水剂,形成强抑制强封堵的聚胺仿油基水基钻井液体系。该体系具有较强的抑制封堵性、抗污染性、润滑性和优良的流变性,同时具有较低的中压失水和高温高压失水,在川西XYHF-1井页岩层现场进行了应用。结果表明,该体系能有效防止页岩层吸水膨胀、缩径垮塌,确保钻井施工安全,在川西页岩气藏开发过程中具有广泛的应用前景。
The oil-based drilling fluid is commonly used in shale gas exploitation,but there are issues of pollution,high costs and so on.Through improving the water-based drilling fluid,the above problems can be solved.The experimental study on engineering geology of T3x5 in western Sichuan shows that this layer is a hard brittle shale,the content of expansive minerals is low and microfractures develop.Borehole instability is the main factor affecting the application of water-based drilling fluid.Through laboratory experiment,the inhibitors,blocking agent and fluid loss additive are selected,forming a polyamine pseudo oil-based drilling fluid system with strong blocking resistance,pollution resistance,lubricity,good rheological property,low middle pressure water loss,high temperature and high pressure water loss,which applies in the shale formation of Well XYHF-1.Results show that this system can effectively provent water from swelling,reducing diameter and sloughing to ensure the safety of drilling construction.This polyamine water-based drilling fluid has a wide application prospect in the shale gas exploitation of western Sichuan.
出处
《断块油气田》
CAS
2014年第6期802-805,共4页
Fault-Block Oil & Gas Field
基金
国家科技重大专项课题"高压低渗气层水平井钻井保护技术"(2011ZX05022-004-02)
关键词
页岩气
硬脆性
井壁失稳
仿油基
水基钻井液
shale gas
hard brittle
borehole instability
pseudo oil base
water-based drilling fluid