A Research And Application On Fracturing Technology For “Three Lows” Reservoir Of Wunan Oilfield In Qaidam Basin

With the Qaidam Basin Wunan oilfield exploration level is rising, the new proven reserves in low permeability, low pressure, the proportion of low-yielding reservoir reserves increased year by year, the original reservoir reconstruction process has been difficult to meet the needs of field production?how effective development of such key issues limiting the development effect of the block is difficult to use reserves and improve the ”three low " reservoir stimulation effect has become. Reservoir geology and rock mechanics analysis results show that small research block reservoir pressure, faults are many and complex, there is a high burst pressure, strong plasticity characteristics?resulting in pressure after flowback difficulties, combined with measures to increase production and historical analysis, flowback problem is to determine the key limitation of oil production, therefore, for Wunan Oilfield in Qaidam Basin ”three lows" characteristic?suitable to carry out applied research technology fracturing the reservoir. First, by laboratory experiments, fracturing fluid system under acidic conditions crosslinking screening test, combined with the reservoir to reduce water sensitivity and stress-sensitive needs identified for different temperature ranges from angry energizing fracturing fluid system, and each index test, reservoir damage analysis and sensitivity analysis, reservoir meet the requirements; secondly, through the proppant settling indoor experiment, the diameter of contrast, production changes after fracturing analysis?comprehensive economic factors to determine the different depths Suitable proppant reservoir; thirdly, designed together for the pump flowback process, nitrogen injection in flowback process, and conducted a field test?contrast can be obtained for a pump associated rapid flowback technology in Wunan Oil is more applicable; finally, to 30 days yield index?use FracproPT software simulation obtained under different conditions of reservoir permeability and fracture parameters optimized construction parameters, the same thickness of the reservoir, with permeability increases, optimize fracture length reduce and optimize the conductivity increases, the optimal amount of sand, displacement sand ratio, sand-carrying fluid volume were 14.6m?3.4m "7min,18.25%?80m" \After field tests and evaluate the effectiveness of measures shows that these measures apply to block this study, a set of final formation fracturing technology can provide technical reference for the "three lows" efficient development of the entire reservoir of Qaidam Basin.