Calibration Of Recovery Of Multi-layer Of Wells In Tight Gas Reservoirs In Linxing Block

In the process of multi-layer production of tight gas reservoirs,it is for the characteristics of poor reservoir properties,high water saturation,strong heterogeneity,and complex seepage laws that it has low recovery.As a result,the recovery of tight gas reservoirs is difficult to be accurately calibrated.Therefore,to establish a more suitable recovery calibration method is of great significance for multi-layer production of tight gas reservoirs.This paper takes the tight gas reservoir in Linxing Block as the research object..Firstly,according to the current situation of multilayer production,physical experiments and numerical simulations are conducted to study the laws of the multi-layer development.It turns out that the backflush of the layers of low pressure has little effect on the recovery of the gas reservoirs,while the water block can’t be ignored if the gas contain water.As a result,a production correction factor is introduced to correct the production capacity of the low pressure backflow layer.By studying the factors that affect the seepage flow of the reservoir such as slippage effect,threshold pressure gradient and stress sensitivity,a multi-layer gas production model considering threshold pressure gradient and stress sensitivity is established.Then,the change rule of the main control factors that affect the recovery with the recovery factor is studied through the gas reservoir engineering method.The gray correlation analysis method is used to obtain the weighting coefficients of the main control factors of tight gas reservoir recovery factor,and a multi-factor evaluation method for tight gas reservoir recovery factor is formed,which is evaluated by developed wells in Linxing tight gas reservoir to verify the rationality of this method.Based on the gas well seepage model,combined with the multi-factor evaluation method for low permeability tight gas reservoir recovery factor,a multi-layer recovery factor-capillary number model is established,which can guide the further development of Linxing tight gas reservoir.The establishment of comprehensive evaluation method for tight gas recovery has fully considered the macroscopic geological characteristics and microscopic seepage characteristics of tight gas reservoirs,and is more in line with the actual characteristics and production status of gas reservoirs,which has certain guiding significance for the evaluation and efficient development of tight gas reservoirs.