Interpretation of single-well pressure transient data from naturally fractured reservoirs


Onur M., Satman A.

IN SITU, vol.22, no.2, pp.181-237, 1998 (Journal Indexed in SCI) identifier

  • Publication Type: Article / Article
  • Volume: 22 Issue: 2
  • Publication Date: 1998
  • Title of Journal : IN SITU
  • Page Numbers: pp.181-237

Abstract

New type curves and procedures for analyzing single-well pressure transient data from a naturally fractured (double-porosity) reservoir are presented. The type curves were motivated by new approximate solutions for the pressure derivative, that apply during the transitional flow period which exists between the two classical semilog straight lines and are generated using the transient interporosity flow models (based on slab-, cylinder- and sphere-shaped matrix blocks) that account for interporosity skin effect. The type curves improve our ability to identify the appropriate model and to determine basic double-porosity parameters from pressure data especially in cases where the interporosity skin effect is important and the data do not exhibit semilog straight lines. In cases where the data exhibit significant wellbore storage and/or multirate effects so that the type curves presented may not be used to resolve some of the basic double-porosity parameters, the use of deconvolution and/or nonlinear regression analysis is discussed. It is shown that the type curves prove useful for obtaining a set of good initial parameter estimates when nonlinear regression analysis is employed for parameter estimation. Both practical and theoretical issues of which the analyst must be cognizant are documented. The applicability of proposed type curves and analysis procedures is illustrated by considering two published field examples.