维北油气田昌68断块钻井完井液优化设计

Optimization Design of Drilling Fluids Used in Block Chang 68 of Weibei Oil and Gas Field

维北油气田昌68断块属于低孔低渗储层,地层水矿化度高,储层极易发生损害,在对储层的基本特征及潜在损害因素进行分析的此基础上,优化设计了新型的广谱"油膜"及理想充填协同增效钻井完井液体系,通过室内评价,可知该体系具有良好的流变性、抑制性、抗污染能力,储层渗透率封堵率可达100%,渗透率恢复值可达到98.1%,初始流动压力明显下降,表明该体系在钻井过程中可有效封堵钻井液中的固相及液相侵入储层,而在开发过程中有助于油气反排,从而整体上提高储层保护效果。

Reservoirs in Block Chang 68 of Weibei Oil and Gas Field belonged to reservoirs with low porosity and low permeability and high salinity in formation water,the reservoirs were easy to be damaged.On the basis of analyzing the fundamental reservoir characteristics and potential damage factors,a new drilling fluid system of broad-spectrum of oil-film temporary plugging with co-acting stimulation of ideal packing was optimized.The laboratory test results show that the drilling fluid system has excellent rheological properties,strong inhibition and anti-pollution ability,high plugging rate of permeability is 100%,permeability restoring rate is 98.1% and initial flow pressure is obviously reduced.It can be used to prevent solid and fluid from invading into formation during drilling,and is favorable for flow back of oil and gas during production.The reservoir protection can be greatly improved.