Study On The Integrated Technology Of Fracture And Gas Test For Compact Sandstone Gas Reservoir In Daning-Jixian Block

Daning-Jixian gas-bearing block is located in the southeast of the Ordos Basin,causing many dense gas sequences and no natural production capacity,and can only increase production through fracturing.In the process of early reconstruction,there are problems such as the mismatch between fracturing design parameters and reservoir conditions,the large damage of fracturing reservoir,the low success rate of field construction,and the failure of gas testing measures after fracturing.Through the analysis and evaluation of the fracturing and gas testing process of the first four wells,it is found that the reservoir can not be well protected because of the long gas testing cycle of single-layer fracturing and trial gas.At the same time,it is found that the difficulty of fracturing the block is that there are many gas sequences and large interlayer interference;The depth of reservoir is shallow,the temperature of reservoir is low,and the performance of fracturing fluid is required to be high.The fracturing fluid is required to meet the characteristics of low temperature cross-linking,low temperature breaking,and rapid return.A complete set of rapid fracturing gas testing technology needs to be formed.By optimizing the function of pipe string,a set of integrated fracturing gas testing pipe string was put forward,which is suitable for the conditions of multi-gas sequence,large interlayer interference and long layered fracturing gas test period,and the matching fracturing fluid system and proppant were optimized.Based on the optimization,the postfracturing integrated gas testing system was optimized,and the integrated fracturing gas testing technology was formed.The fracturing fluid performed well in crosslinking at low temperature,carrying capacity,gel breaking and fast flowback,which greatly shortened the gas test period.Compared seven wells using the integrated fracturing gas testing technology proposed in this paper with three wells without the technology in the tight gas reservoir of Daning-Jixian block,we found that the technology greatly shortened the gas testing period and protected reservoirs effectively,and all the seven wells achieved high production rate and 100%construction success rate,which helped provide a reliable basis for subsequent reservoir evaluation,well selection and construction technology selection.