WORLD EXPERIENCE IN USING VARIOUS MULTISTAGE HYDRAULIC FRACTURING ASSEMBLY. EXPERIENCE AND PROSPECTS AT RUSSIAN FIELDS

The problem of choosing the most optimal scheme for low-permeability reservoirs production intensification is relevant for Russian fields. That is why subsoil users are actively introducing multi-stage hydraulic fracturing (MSHF) for wells with horizontal completion. Active introduction of multi-stage hydraulic fracturing allows involving hard-to-recover hydrocarbon reserves in development, increasing the drainage area, and increasing the hydrocarbon recovery factor and, consequently, the economic efficiency of field development. The relevance of studying MSHF technologies with appropriate equipment and tools is due to the optimal arrangement of equipment and tools, the absence of the need for additional downhole work. For MSHF successful implementation, specialized equipment is required that ensures effective preparation and implementation of this technology. Today, there are many technological possibilities for MSHF, well completion arrangement options, which are constantly being improved. MSHF implementation methods differ in the sequence of operations during the work and the arrangement of downhole equipment. The aim of this article is to consider and analyze the efficiency of common technologies that can be applied to Russian fields with hard-to-recover reserves. This article presents various design options for performing multistage hydraulic fracturing operations, considers the procedure for preparing a well before the operation, the cycle of the operation itself, the features of each technology, and the experience of using this or that technology in the world by various companies. The most studied, traditional technology is considered to be multistage hydraulic fracturing using ball couplings, with various versions of the balls (soluble, insoluble) due to the simplicity of the technology, its study, relatively low cost, and the ability to initiate a precise fracture location. The advantage of ball-less systems is the ability to perform repeated hydraulic fracturing in any sequence, selective control of couplings, and an unlimited number of stages. Various types of designs and tools offered by Russian companies are considered. The success and efficiency of multistage hydraulic fracturing using this or that technology is confirmed at Russian fields.