HIBDRILL钻井液在BZ25-1油田的研究与应用

Study of HIBDRILL Drilling Fluid and Its Application in BZ 25-1 Oilfield

BZ25-1油田油气层埋藏深,地质构造复杂,主力油层沙河街组为低孔低渗、异常高温高压储层,泥浆安全密度窗口窄,易发生井漏、垮塌、溢流、井喷等复杂事故。针对前期出现的问题,室内研究了HIBDRILL钻井液体系,并对其流变性、封堵性、油层保护效果、渗透率恢复等性能进行了评价。室内研究及现场应用表明,该体系与一期作业的油基钻井液相比明显提高了钻井速度,降低了使用钻井液密度,成功解决了BZ25-1油田沙河街组压差卡钻、泥页岩垮塌以及低孔低渗储层保护等复杂问题。

Oil and gas reservoirs were buried deeply and the geological structure was very complex in BZ 25-1Oilfield.The main reservoir of Shahejie Formation was an abnormally high temperature and pressure reservoir with low porosity and low permeability,its safe window of mud density was narrow,by which serious accidents,such as lost circulation,wellbore collapse,overflow and blowout were easily induced.To solve these problems,a new drilling fluid-HIBDRILL is studied and formulated in the laboratory,its rheology,sealing ability,the effect of formation protection and permeability recovery value were evaluated.Laboratory experiments and field application show that HIBDRILL can obviously reduce mud density and risk of lost circulation and increase drilling rate comparing with the performance of the first drilling operation,it is used for successfully solving many problems during drilling operation,such as differential pressure sticking,collapse of shale and reservoir damage of low porosity and low permeability reservoirs.