EXPERIMENTAL STUDY OF ACID FRACTURING USING NON-ACTIVE NITRIC POWER FLUID IN SANDSTONE RESERVOIR

Traditional standpoint thinks that it is not viable for sandstone reservoir to proceed acid fracturing, however acid fracturing has been succeeded in sandstone reservoir in the last few years. experimental of acid fracturing in sandstone reservoir was developed, and the results can guide the practice. The non-active nitric powder is a new material for acidizing which exhibits non-active in normal state but can decompose strong oxide HNO3 after activated, which can violently and locally dissolve rock and blocked material without destroying formation structure, and break through oil path and improve formation permeability. Comparing with conventional acidizing techniques, non-active nitric power fluid can remove inorganic plugging, oil and water plugging, penetrate deeply,and has less recontamination. So, useing non-active nitric power fluid as treatment fluid. Through analyzing of dissolution capability, flow conductivity of crack after acidizing, configuration after etching by acid and analyzing of the factor which effects the flow conductivity, demonstrate that it is viable for sandstone reservoir to proceed acid fracturing.