试井解释在火山岩气田A井应用研究

Applied Study on Well Testing Interpretation to A Well in Volcanic Rock Gas Field

通过对D气田A井中途测试、地层测试、系统试井测试、试采测试资料解释分析,认为该井火山岩储层物性好、渗透率高、厚度大,具有高产的物质基础。结合地质情况,选择部分射开模型进行试井解释,证明了火山岩储层纵向上的连通性。解释表皮系数非常大,表明该井在钻井、完井过程中,泥浆和压井液侵入地层,对地层污染堵塞十分严重,制约了气井自然产能的发挥。随着生产时间的持续增加,表皮系数逐渐变小,有明显的解堵现象。在钻井过程中,为了避免泥浆对火山岩地层伤害,首先应该缩短钻井周期、降低泥浆的浸泡时间,减少泥浆侵入地层的机会;其次严格执行平衡钻井或欠平衡钻井技术标准。

Through data interpretation and analysis on a well in D gas field of open hole test,well test,system well testing and production test,it is thought that the volcanic rock of this well has good reservoir physical properties of high permeability and large thickness and higher yield. Combined with geological condition,partial perforated model is selected to well test interpretation to prove that the longitudinal connectivity of the volcanic rock reservoir. The skin factor is very large,that shows the mud and killing fluid invaded the formation in the process of drilling and completion to cause the formation seriously pollution,which severely restricts the play of gas well's natural productivity. With the continuous increase of production time,skin factor gradually becomes smaller,having a clear solution blocking phenomenon. In the process of drilling,in order to avoid damage of the mud for volcanic formation,firstly,drilling cycle should be shortened,the mud soak time is lowered to reduce the chance of mud invasion formation. Secondly,balance drilling or under-balanced drilling technology standards should be carried out strictly.