Single-layer multi-seam fracturing technology based on stereoscopic staggered oriented perforating technology

Abstract

The invention discloses a single-layer multi-seam fracturing technology based on a stereoscopic staggered oriented perforating technology, and belongs to the field of oil extraction in low-permeability oilfields. The fracturing technology at least includes the following steps: (1), shaft optimization; (2) optimization of perforation parameters; (3) optimization of oriented perforating manner and construction scale; (4), fracturing construction. According to the invention, the perforation parameters are optimized to guarantee that a single sand body with the reservoir thickness of 30 m is divided into more than four sections after fracturing of separate layers; the stereoscopic staggered oriented perforating construction manner enables the orientations of perforations on adjacent two sections to be different, crack initiation and expansion of cracks at each section are at different orientations, communication of cracks is avoided, construction scale such as sand quantity, discharge and liquid quantity, and fracture scale are improved, and the reservoir reformation volume is increased, so that the discharge volume is enlarged, and well yield is increased; more than four layers of immovable string tools for fracturing of separate layers are adopted for construction, so that fracture of more than four sections can be completed by the pipe column in one trip, and the construction efficiency is improved.

Description

technical field [0001] The invention relates to the field of oil recovery in low-permeability oilfields, in particular to a fracturing process for realizing single-layer multi-fracture by means of three-dimensional interlaced directional perforation technology. Background technique [0002] Low-permeability oilfields refer to oilfields with low permeability, low abundance and low single-well productivity. Ultra-low permeability reservoirs mainly refer to reservoirs with a permeability of less than 1.0×10-3 μm2, a reservoir depth of about 2000m, and a single well production of about 2.0t / d. They are typical low-permeability, low-pressure, and low-abundance reservoirs. [0003] In the fracturing process of low-permeability reservoirs, when the fracture length increases to a certain extent, it is not obvious to increase the reservoir production simply by increasing the fracture length. Perforation is used to control the orientation of fracture initiation. Perforation is the op...

AI Technical Summary

Problems solved by technology

In the conventional fracturing technology, the multi-stage sand fracturing technology can increase the vertical production degree of thick oil layers, but the lateral penetration depth is limited, that is, the fracture height is large, but the fracture length is small, and the fracture drainage volume is limited. The production increase is small; in the multi-fracture fracturing technology, the multi-stage multi-fracture fracturing technology of deviated wells can increase the number of partial pressure stages as much as possible compared with multi-stage sanding, but it is limited by the favorable conditions of well deviation and wellbore orientation and the fracturing process. Due to the limitation of fracture scale, the scope of application and the improvement of single well production are limited; the directional perforation multi-fracture fracturing technology is limited by the previous technology, and can only realize partial pressure in two to three stages

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