DOI: 10.24412/2076-6785-2023-6-39-46
Abstract
The features of multi-stage hydraulic fracturing at a low-temperature carbonate object (10–16°C), which relate to hard-to-recover reserves, are presented in the paper. Earlier acid fracturing and large volume hydrochloric acid treatments were applied to stimulate the object. However, these technologies appeared to be economically inefficient as low-temperature carbonates do not react well with hydrochloric acid and fluid systems on its basis. А number of single and multi-stage proppant hydraulic fracturing was carried out in wells with a horizontal completion. But there were high levels of gas in well production according to the results of the well launch. This shows a fracture breakthrough into the underlying gassaturated
formation. 3D geomechanical modelling of the object is carried out in order to increase the efficiency of the hydraulic fracturing operation. Due to introduction of a geomechanical model hydraulic fracture breakthrough into the underlying gassaturated formation was managed to avoid, and the difference between planned and actual ISIP and Pcl values does not exceed 2 %. Cross modelling of the geomechanical model and the hydraulic fracturing model allowed to choose volumes and rates of injection. That allows to implement the tasks set by the geological service for HF engineers. During fracturing operation with sleeves BPS the line-up with a selective two-cup packer С2С is used. It is lowered by 73 mm tubing.
The work performed ensured positive results of the pilot project, and the work success has been confirmed by the results of post-frac well startups. The resulting start-up rates confirm economic development of the field.
Materials and methods
The features of multi-stage hydraulic fracturing at a low-temperature carbonate object, are presented in the paper. The accuracy of geomechanical modeling has improved due to extended laboratory studies of the core to determine the Bio constant and the anisotropy of rock elastic properties. To confirm the success of hydraulic fracturing operations, a complex of hydrodynamic and geochemical studies was performed.
Keywords
carbonate reservoir, multi-stage hydraulic fracturing, low-temperature, mechanical earth models
