Carbon dioxide composite layered huff and puff pipe column

Abstract

The invention relates to a carbon dioxide composite layered huff and puff pipe column. The carbon dioxide composite layered huff and puff pipe column comprises an oil pipe body with the top end capable of communicating with a ground injection device, and further comprises a carbon dioxide composite layered injection part connected to the oil pipe body in series, wherein the carbon dioxide composite layered injection part can conduct two times of opening and closing reversing through two times of ball injection so as to inject carbon dioxide and steam in a layered mode; an upper packer is arranged on the oil pipe body in series and used for packing an upper oil layer and an annulus above the upper oil layer; the oil pipe body is sleeved with a hydraulic interlayer packer, and the interlayer packer is used for packing the annulus between a lower oil layer and the upper oil layer; the bottom end of the oil pipe body is connected with a screen pipe capable of communicating with the lower oil layer, and the bottom of the screen pipe is closed; and a constant-pressure ball seat is arranged at a position, located between the interlayer packer and the screen pipe, in the oil pipe body. Layered injection of carbon dioxide injection and steam huff and puff can be achieved, the injection allocation amount of each layer can be accurately controlled, the producing degree of injected fluid in the longitudinal direction of an oil well is increased, and the oil well recovery efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of injection and production of oil and gas wells, in particular to a carbon dioxide composite layered huff and puff string. Background technique [0002] Many blocks of heavy oil in Liaohe Oilfield are already in the late period of high steam huff and puff. With the increase of steam huff and puff cycle, formation deficit increases, production declines rapidly, formation water increases, heat utilization rate decreases, and development cost increases. The production efficiency becomes worse; conventional water flooding develops heavy oil reservoirs due to the high viscosity of crude oil, large oil-water flow ratio, serious interlayer heterogeneity, and channeling of injected water along high-permeability layers, resulting in small swept volume, oil displacement efficiency and recovery. The degree is low, and the water injection development effect is poor. Injecting carbon dioxide into heavy oil reservoirs c...

AI Technical Summary

Problems solved by technology

At present, this technology can only achieve general injection in the application process, and cannot realize layered injection, and cannot realize fine injection for multiple sets of oil wells, resulting in the problem that the uneven longitudinal production of oil wells affects oil well productivity and oil recovery.

Images