Analysis for pressure falling down at post fracture influenced by temperature

Abstract

A kind of mathematic model to simulate temperature and pressure performance, interference between them and influence from compressibility of fracturing fluid testing in small type of fracture are presented. Numerical value solution and approximate solution of PKN model is used to calculate geometry parameter of the crack before well's closing, while, linear and elastic theory is utilized to calculate width of crack through simulating pressure. The simulating effect shows that crack temperature has obvious change at small scale fracture testing period. Comparing with uncompressible fracturing fluid, the higher of the pressure of compressible fluid, the much slow for the descent speed. If the fluid is compressible, the sieve coefficient computed by Nolte pressure fall down analysis method is much little. Farther, the study also indicates that the error of sieve coefficient calculated by later time of pressure data at well closing period is much small.