Long Zhangliang, Zhong Jingmin, Hu Yongzhang, et al. Application of geomechanics in deep shale gas development in Yongchuan[J]. Petroleum Reservoir Evaluation and Development, 2021, (1): 72-80. DOI: 10.13809/j.cnki.cn32-1825/te.2021.01.010.
Application of geomechanics in deep shale gas development in Yongchuan
Yongchuan deep mountain shale gas block is located in Huayingshan fold belt
which is a low anticline group with broom like spreading to the south. The structural folds are strong and the faults are developed. The target layer of Longmaxi Formation has the characteristics of great difference in burial depth
high ground pressure and ground temperature and large difference in horizontal stress
while the crossing layer has strong abrasiveness
easy instability of well wall and poor drillability. The lack of early geological knowledge leads to low drilling time
long construction period and frequent complex situations
and the fracturing effect of multiple wells is not ideal. In order to solve the main problems faced by Yongchuan work area
researches on the geomechanical parameters
such as drillability
hardness
abrasiveness laboratory experiments
drillability profile establishment
formation three pressure prediction
3 D in-situ stress finite element
simulation and fracture propagation simulation under different horizontal stress difference modes
and horizontal well geological engineering double sweet spot prediction
have been conducted respectively. The results show that the formation drillability level is high
the safe drilling fluid density window is narrow
the difference of in-situ stress direction is large
and the formation of hydraulic fracturing network is affected by high stress difference.Based on the research results of geomechanics
the engineering technology has been adjusted. The drilling speed and fracturing production increase effect are obvious
which has reference significance for the development of deep shale gas in South Sichuan.