Fire flooding oil extraction method for vertical well gas-injection horizontal well oil extraction

Abstract

The invention relates to a viscous oil exploitation method, in particular to a fire flooding oil exploitation method used for gas injection by a vertical well and oil exploitation by horizontal well. The invention adopts the compound well-layout manner of steam injection by vertical wells and oil exploitation by horizontal wells, which means that six vertical wells are for gas injection and two oil exploitation wells for oil exploitation, or nine vertical wells for gas injection and three oil exploitation wells for oil exploitation. When the wells are drilled, the vertical wells are drilled until they reach the half thickness of an oil layer, and gas is injected above the half thickness of the oil layer. The horizontal wells are under the half thickness of the oil layer. The gas-cap pressure produced by burning of the gas-injected oil layer of the above vertical wells presses the crude oil of the lower part, while the crude oil flows to the horizontal well sections by the self-gravity and then is exploited from the exploitation wells . The invention overcomes the shortcoming that gas channeling can be easily formed horizontally along an oil layer in a high-penetration passage inside the oil layer, and promotes the final recovery rate of the oil layer through fire flooding by fifteen percent.

Description

Technical field: [0001] The invention relates to a heavy oil production method; in particular, a fire flooding oil production method used for oil production in vertical wells with steam injection and horizontal wells. Background technique: [0002] Heavy oil is an important part of petroleum hydrocarbon energy, and has a huge potential several times higher than conventional crude oil resources. my country is rich in heavy oil resources and widely distributed. Liaohe Oilfield is the main heavy oil development area in my country. There are many types of reservoirs and the burial depth varies greatly. (See Petroleum Industry Press, Han Xianqing Enhanced Oil Recovery Basis 1993 131 157-160) In addition, due to the high viscosity and high density of heavy oil, the flow resistance during production is large, the displacement efficiency and volumetric oil efficiency are also low, and it is difficult to use conventional method to mine. Although a small amount of underground crude ...

AI Technical Summary

Problems solved by technology

Although a small amount of underground crude oil can be recovered by adopting thermal recovery methods such as steam flooding, steam huff and puff, burning oil layers and heavy oil fire flooding, steam injection in vertical wells, and oil production in vertical wells, due to conflicts between heavy oil layers and intralayer conflicts , Plane contradiction, uneven lithology of heavy oil formations, and lithological high-permeability bands, so it is difficult to use steam to heat the wellbore and use SIGD oil recovery method to overcome the phenomenon of gas stringing on the rock formation plane during steam injection, steam is easy Flowing in layers with higher permeability, the low-permeability lithology flooding effect is not ideal, which ultimately affects the improvement of recovery. If the oil recovery method of fire flooding horizontal wells is used instead, the influence of high-permeability zones can be changed and the final recovery can be improved. The rate is about 15%. This method has been reported in the combination of injection wells and horizontal production wells in the horizontal section air injection process in the fifth issue of volume 10 of special oil and gas reservoirs in October 2003, but the horizontal section air injection (THAI) Refers to the thin oil medium, and the well group combination is also fundamentally different from this application

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