Parameter Optimization of Segmental Multicluster Fractured Horizontal Wells in Extremely Rich Gas Condensate Shale Reservoirs

Wei Zhipeng,Wang Tao,Han Guannan,Wang Jinwei,Liu Rumin

doi:10.3389/feart.2021.730080

Abstract

For economic and efficient development of extremely high-condensate shale gas reservoirs, a numerical model of segmental multicluster fractured horizontal well was established considering the effect of condensate and desorption, and the optimization of fracturing segments, fracturing clusters, half-length of main fracture, fracture permeability, fracture mesh density, and fracture distribution patterns were studied. It is indicated that the horizontal well whose design length is 2,700 m performs best when it has 43 fracturing segments with three clusters in each segment and the fracture permeability is 300 mD. The production capacity of horizontal wells is positively linearly correlated with the half-length of fractures. Increasing fracture half-length would be an effective way to produce condensate oil near wellbore. An effective fractured area can be constructed to remarkably improve productivity when the half-length of the fracture is 50 m and the number of secondary fractures is four in each segment. On the basis of reasonable fracture parameters, the staggered type distribution pattern is beneficial to the efficient development of shale gas-condensate reservoirs because of its large reconstruction volume, far pressure wave, small fracture interference, and small precipitation range of condensate.

Highlights

High-condensate shale gas reservoirs, whose content of condensate can be as much as 600 g/m3, undergo more sophisticated phase behavior compared with ordinary shale gas reservoirs, where issues such as low porosity, low permeability, adsorption, and desorption are investigated
Current investigations on extremely high-condensate shale gas reservoirs hardly consider the complex fracture system brought by segmental multicluster fracturing on the productivity of shale gas
The analysis shows that when there are fewer than two secondary fractures, the fracture network density is small, the pressure wave propagation is slow, and the spread range is small

Summary

INTRODUCTION

The effective thickness of the Duvernay shale reservoir in Simonette block of Western Canada Basin is 30 to 45 m, TOC is 2% to 6%, effective porosity is 3% to 6%, and permeability is 0.0001 to 0.0003 mD. Numerical simulations in which the number of secondary fractures in a single fracture stage is 0, 2, 4, 6, 8, and 10 are conducted, respectively, to simulate the development effect of staged fractured horizontal wells in shale condensate gas reservoir under different fracture network densities. It can be seen from the cumulative oil and gas volume curves of different numbers of secondary fractures (Figure 10A) that when the number of secondary fractures increases from 0 to 2, the cumulative oil and gas volume does not increase significantly. The relationship between pump procedure and fracture patterns on the basis of stress interference is a significant issue

CONCLUSION

DISCUSSION

DATA AVAILABILITY STATEMENT