The Optimization Of Fracture Parameters For Fractured Horizontal Wells

At present,due to the characteristics of “low porosity,low permeability,low pressure,low abundance,strong heterogeneity” in the Sulige gas field,single wells usually have no natural runoff and are difficult to product.Horizontal wells need to be used for staged fracturing.This can effectively increase production.In order to improve the fracturing effect,it is necessary to optimize fracture parameters.Nowadays,the studies of conventional fracture parameter optimization are all equal spacing,equal lengths.And unequal-spacing is also studied under injection well network conditions.Ignoring the fact that the characteristics of high yield at both ends and low yield at intermediate.Consider this feature,this paper propose reducing fracture spacing and lengthening fracture length at the two ends of the well-bore in the fractured horizontal well.At the same time,the theoretical model used for the optimization of fracture parameters is under the condition of horizontally homogeneous.However,in the formation,especially in the Sulige gas field,with horizontal heterogeneity,the part where gas saturation is relatively higher or permeability is relatively lower than other parts is the "fracturing sweet pot" as defined herein.Aiming at the characteristics of lateral heterogeneity of gas reservoirs,a fracturing numerical simulation model for the variation of the gas reservoir parameters along the horizontal well-bore was established to study the effect of different “fracturing sweet pot”locations and to optimize the fracture parameters.The results show that the effect of reducing fracture spacing and lengthening fracture length at the two ends of the well-bore is better than that of regular equal-length and equal-spacing fracture arrangement.The effect of fracturing arrangement is related to the distribution of gas saturation and permeability in the gas reservoir model;The effect of aiming at “fracturing sweet pot” to arrange the fracture is better than that of conventional equal-length equal-spacing arrangement of fracture.