A novel method for calculating the dynamic reserves of tight gas wells
considering stress sensitivity is under consideration. - Take the ZT
block in Northwest Sichuan as an example
- Chang-Hao Chen,
- Jing Luo,
- Jian Cao,
- Xu-Chen Li,
- Lin-Feng Cai,
- Tan-Yin Zhu
Abstract
The accuracy of dynamic reserve calculation in gas fields is of
significant importance for the rational and efficient development of oil
and gas fields, as well as the establishment of gas well production
allocation schemes. The reservoir in the ZT block in the northwest of
Sichuan is tight and highly heterogeneous, with complex gas-water
distribution and significant differences in gas well test production
rates and rapid decline rates. In order to accurately calculate the
dynamic reserves of such tight water-bearing gas wells, this study
focuses on the tight water-bearing gas reservoirs in the ZT block in the
northwestern region of Sichuan. Rock core X-ray diffraction experiments,
constant rate mercury injection experiments, and reservoir rock stress
sensitivity experiments were conducted. Based on the experimental
results, corrections were made to the porosity and permeability of rock
samples under effective stress conditions using a binary linear
regression method. These corrected parameters were then incorporated
into the water-sealed gas material balance method, establishing a new
method for calculating dynamic reserves in water-bearing tight gas
reservoirs under stress-sensitive conditions. Utilizing reservoir
parameters and production data from the ZT block, the results of the
material balance method, well testing analysis method, and mathematical
statistical method were compared with the results obtained using the new
method. The dynamic reserve calculations for water-bearing tight gas
reservoirs considering stress-sensitive conditions showed smaller
relative errors and more accurate results.