تجزیه و تحلیل گذرای فشار از تغییر شکل متوسط ​​فراکتال

The assumption of constant rock properties in pressure-transient analysis of stress-sensitive reservoirs can cause significant errors in the estimation of temporal and spatial variation of pressure. In this article, the pressure transient response of the fractal medium in stress-sensitive reservoirs was studied by using the self-similarity solution method and the regular perturbation method. The dependence of permeability on pore pressure makes the flow equation strongly nonlinear. The nonlinearities associated with the governing equation become weaker by using the logarithm transformation. The perturbation solutions for a constant pressure production and a constant rate production of a linear-source well were obtained by using the self-similarity solution method and the regular perturbation method in an infinitely large system, and inquire into the changing rule of pressure when the fractal and deformation parameters change. The plots of typical pressure curves were given in a few cases, and the results can be applied to well test analysis.

Numerous experiments have proved that the formation of oil reservoir and the fracture network distribution of fractured reservoir are fractal structures. Therefore, the flow theory of fractal reservoir has been developed and applied to oilfield. Fluid flow in hydrocarbon reservoirs and ground water aquifers have been traditionally studied by assuming the formation permeability is constant[1-6]. These assumptions in the fluid flow analysis have given good results in many situations, but with increasing exploitation of petroleum and geothermal resources from low-permeability and fractured formations, theseassumptions need to be re-evaluated. Kikani[7] presented the flow model for cylindrical flow systems of deformed media. A perturbation technique was applied to determine the approximate solution and analyze the flow characteristics of deformed media reservoir. Yeung[8] considered the spherical flow problem of deformed media reservoir. A simple technique was applied to obtain approximate solutions, but the error is large. The generalized pseudo pressure function was introduced to characterize the gas flow in pressure-sensitive reservoir[9]. The flow analysis for stress-sensitive reservoirs with double porosity was studied[10-16]. But the flow analysis for stress-sensitive fractal reservoirs has not been performed. Radial and spherical flow in homogeneous reservoir are special cases of fractal reservoir[1] ( = or 3 , and f d

1) Fractal dimensions have been introduced to the flow equation of fluids in fractal reservoirs. The flow model has more extensive adaptability compared with the traditional ones. (2)The similarity solutions for the flow models of fluid in fractal reservoir with both the constant rate production and the constant pressure production have been obtained by using similarity solution method. (3) The perturbation solutions for a constantpressure production and a constant rate production of linear-source well have been obtained by using the regular perturbation method in an infinitely large system. (4) With time increasing, the effect of D becomes remarkable. With increasing D