Steam assisted gravity drainage technology of double-branch horizontal well

Abstract

The invention relates to a thermal recovery technology of a branched horizontal well, in particular to a steam assisted gravity drainage technology of a double-branch horizontal well. The steam assisted gravity drainage technology of the double-branch horizontal well comprises the following steps that (1) in the process of well completion of the double-branch horizontal well, an upper directional horn-shaped opening is installed, and the slope direction of the upper directional horn-shaped opening is kept to be consistent with the direction of a hollow inclination guiding device; (2) a packer and a seal joint are installed in a branch well Z1 and a branch well Z2 respectively, and are used for sealing the branch well Z1 and enabling the branch well Z2 to form an annular space, and pressure leakproofness is kept. According to the steam assisted gravity drainage technology of the double-branch horizontal well, due to the fact that the technical advantages of the double-branch horizontal well are made full use of, the purposes that the recovery ratio of heavy oil and the recovery ratio of super heavy oil are increased, the oil production rate of heavy oil and the oil production rate of super heavy oil are increased, the well drilling cost and the oil production cost are reduced, the hard-to-recover reserve is used economically, and the workload of two common horizontal wells is accomplished through one double-branch horizontal well are achieved. The defects that according to an existing SAGD technology, two horizontal wells need to be drilled, and the well drilling cost and the oil production cost are high are overcome.

Description

Technical field: [0001] The invention relates to a thermal recovery technology of a branched horizontal well, in particular to a steam-assisted gravity drainage technology of a double-branched horizontal well. Background technique: [0002] In recent years, lateral wells have been used on a large scale at home and abroad to develop heavy oil reservoirs, buried hill reservoirs, low-permeability reservoirs and remaining oil in old areas to tap the potential, greatly improve the recovery rate and oil production speed, reduce drilling costs and oil production costs, and have achieved great success. Huge economic and social benefits. [0003] At present, most of the heavy oil and ultra-heavy oil still need to be recovered by thermal recovery. Steam-assisted gravity drainage (SAGD) is a thermal recovery method with a high recovery rate. Drill a pair of horizontal wells, one above and one below, with a certain distance between them. The upper well is used to inject steam into the...

AI Technical Summary

Problems solved by technology

It overcomes the shortcomings of the existing SAGD process that requires two horizontal wells to be drilled and the cost of drilling oil production is high

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