Study On Concentric Three - Layer Stratified Steam Injection In Heavy Oil Reservoir

As the rapid growth of the oil demand and the further-exploited petroleum condition, heavy oil reservoir development has become increasingly important. Steam injection thermal recovery of heavy oil exploitation is an effective method. Due to that and commingled thermal recovery initial injection, results uneven involved reservoir between layers, overly steam injected in the latter period of steam injection, and in the end, reduces the oil recovery.Stratified steam injection technology is an important way to relieve interference between the steam flooding layer and improve steam flooding effect. As the first discussed part of this paper, the technology mainly includes the hierarchical quantitative steam injection, layered steam, eccentric and concentric layer separate layer steam injection steam injection. Through the analysis we know what defect has in this technology, which is the inconvenient of unbalanced steam injection and limit of ancient rip. Then we proposed the theory of separate layer steam injection technology of three concentric layer steam injection technology in concentric, and we designed underground corresponding tools. The design of the steam injection string has been achieved that a column injected the three layer steam at the same time, wherein the two layer stratified steam control principle of the steam injection rate, breaking the concentric layer steam injection technology can be divided into two layers of limitation. On the ground with concentric double tubing wellhead device can directly adjust the layer steam injection volume, no tube or salvage operations. Through the redesign of the main tool and the corresponding column strength calculation to ensure the three concentric layer steam injection technology design reliability.By the analysis of the distribution of the pressure and dryness during steam flooding, on which, we established the calculation model of wellbore pressure and dryness, and we calculated on some models, analyzed and tested. This method provided a theoretical basis for the design of heavy oil reservoir with three concentric layer steam injection technology also, can be used for design and analysis of steam injection wells operating parameters. This paper successfully completed the application of three layer steam injection technology, effectively improved the vertical producing degree of reservoir and provided a new method to enhance heavy oil thermal recovery post-effective oil recovery.