Heavy oil reservoir exploitation method

Abstract

The invention provides a heavy oil reservoir exploitation method. The heavy oil reservoir exploitation method comprises that a vertical well-horizontal well row-column type well net is arranged in the mine section of a heavy oil reservoir the vertical well-horizontal well row-column type well net comprises vertical well rows and horizontal wells which are distributed alternatively, the well spacing a between adjacent vertical wells in each vertical well row is equal, the well spacing b between each vertical well and the adjacent horizontal well is equal, the well spacing c between adjacent vertical wells at two sides of one horizontal well and in adjacent vertical well rows satisfies the formula c= the square root of (a<2> / 4+4b<2>), steam is injected into all vertical wells and horizontal wells, steam huff and puff production is carried out until the stratum temperature reaches the temperature corresponding to the inflection point of a crude oil viscosity-temperature curve, the steam injection intensity of the vertical wells ranges from 100 t / m to 120 t / m, the steam injection intensity of the horizontal wells ranges from 15 t / m to 20t / m, after the steam huff and puff production, the vertical well arranged in the central position is selected as a steam injection well, after the oil layer is ignited, air is injected into the steam injection well, and linear fire flooding production is carried out. According to the invention, problems that in the heavy oil reservoir, the connectivity of injection and production wells is poor, and the recovery ratio is low are solved.

Description

technical field [0001] The invention relates to the field of oil exploitation, in particular to a method for exploiting heavy oil reservoirs. Background technique [0002] So far, steam assisted gravity drainage (SAGD), steam stimulation (CSS) and steam flooding (SF) have become the main methods for recovering heavy oil. Steam-assisted gravity drainage technology is suitable for oil reservoirs with continuous oil layer thickness greater than 15 meters and undeveloped interlayers. Theoretically, the ultimate recovery rate can reach 55% to 60%. The field test carried out by Fengcheng Oilfield shows that due to the high viscosity of crude oil and the large seepage resistance between wells, the cycle preheating stage lasts for a long time and the steam consumption is large; Oil production is lower and oil vapor is lower. Steam huff and puff technology is a mature technology with a wide range of applications, easy operation. However, for heavy oil reservoirs, there are the fol...

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Problems solved by technology

[0004] The main purpose of the present invention is to provide a method for mining heavy oil reservoirs to solve the problems of poor connectivity between injection and production wells and low recovery factors in heavy oil reservoirs due to high crude oil viscosity

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