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引起储集层伤害的主要原因是钻井作业期间的微粒运移。叙述了这样一种实验,用一种动态钻井液循环体系测试三种钻井液对土耳其东南地区砂岩和石灰岩渗透率的降低率。按API标准准备非处理膨润土流体、聚合物-XT、PAC-XC三种钻井液各11份,用于11种不同的压力下的实验。岩心塞抽真空后用盐水饱和,并测定初始渗透率。循环钻井液2~3h,然后从另一端测量岩心塞的恢复渗透率。由于细颗粒侵入了岩心塞,降低了岩心塞的渗透率。最终渗透率和初始渗透率的差值与初始渗透率的比值定义为伤害比,用这个概念来分析渗透率的降低。用含有PAC-XC的钻井液,石灰岩岩心的伤害比最低,它的渗透率伤害比为32%,而同样条件下砂岩岩心造成了46%伤害比。非处理膨润土钻井液对砂岩岩心的伤害比最高,为78.4%。确定了造成最低伤害比的最优钻井液。伤害比与滤失压力的指数关系式应用于实验数据中。实验数据与相关结果彼此很一致。这个关系方程通过两边取自然对数而线性化,确定了每一种钻井液的相关系数。得到约0.90的高回归系数。这个关系式能够为砂岩和石灰岩岩心塞进一步确定不同压力下的伤害比。
The main cause of reservoir damage is particle migration during drilling operations. Describes an experiment in which a dynamic drilling fluid circulation system was used to test the rate of decrease of the permeability of sand and limestone from three drilling fluids to the southeastern Turkey. According to the API standard preparation of non-treated bentonite fluid, polymer-XT, PAC-XC drilling fluid 11 each for 11 different pressures under the experiment. The core plug was saturated with brine after evacuation and the initial permeability was measured. Circulation drilling fluid 2 ~ 3h, and then measured from the other end of the core plug recovery permeability. As fine particles invade the core plug, the permeability of the core plug is reduced. The ratio of the difference between the final permeability and the initial permeability to the initial permeability is defined as the injury ratio, and the concept is used to analyze the reduction in permeability. The limestone core has the lowest damage ratio with drilling fluids containing PAC-XC, which has a permeability damage ratio of 32%, while sandstone cores cause 46% damage under the same conditions. The highest damage ratio of non-treated bentonite drilling fluid to sandstone core was 78.4%. Identified the best drilling fluid that caused the lowest damage ratio. The exponential relationship between damage ratio and filtration pressure was applied to the experimental data. Experimental data and related results are consistent with each other. The relational equation is linearized by natural logarithms on both sides to determine the correlation coefficient for each drilling fluid. A high regression coefficient of about 0.90 was obtained. This relationship can further determine the damage ratio for different pressures for sandstone and limestone core plugs.