Hot water assisted gravity drainage method for mining high pour-point oil deposit

Abstract

The invention relates to a hot water assisted gravity drainage method for mining a high pour-point oil deposit. The hot water assisted gravity drainage method for mining the high pour-point oil deposit comprises the following steps of: drilling a horizontal production well at the bottom of an oil reservoir of the high pour-point oil deposit; drilling two horizontal injection wells on the top of the oil reservoir of the high pour-point oil deposit; performing artificial fracturing and fissure forming on the horizontal injection wells and the horizontal production well; performing hot water huff and puff circulation preheating by using the horizontal injection wells and the horizontal production well simultaneously; and after circulation preheating is finished, starting to inject and produce continuously, namely continuously injecting hot water at the temperature of 100 DEG C by using the horizontal injection wells, and continuously producing by using the horizontal production well. The hot water assisted gravity drainage method for mining the high pour-point oil deposit can be applied to the high pour-point oil deposit of which the effective thickness is greater than 10 meters on large scale, and the well productivity and the recovery efficiency are improved.

Description

technical field [0001] The invention relates to a hot water assisted gravity drainage method, in particular to a hot water assisted gravity drainage method for exploiting a high pour point oil reservoir, and belongs to the technical field of oilfield exploitation. Background technique [0002] High pour point oil reservoirs are oil reservoirs characterized by "two highs and one low" (high wax content in formation crude oil, high wax precipitation point, and low production). All are distributed, and the geological reserves are more than 200 million tons, which has broad development prospects. [0003] When the crude oil in the high pour point oil reservoir is above the wax precipitation temperature point, all the wax dissolves in the crude oil and flows together with the crude oil. The crude oil has low viscosity, high flow capacity, and good development effect. When the temperature of the crude oil is lower than the wax precipitation point, a large amount of wax crystals in...

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Problems solved by technology

[0005] (1) Since more than 80% of high pour point oil reservoirs are currently developed by conventional cold water injection, with the continuous development of oilfields, the amount of injected water continues to increase, the formation temperature gradually decreases, a large amount of wax is precipitated in crude oil, cold damage and blockage of the reservoir The phenomenon is getting more and more serious, the water absorption index of reservoir water injection wells drops rapidly, and conventional plugging removal measures can only alleviate the plugging near the wellbore, but cannot significantly improve the seepage capacity in the far part of the oil layer, resulting in worsening plugging removal effect; using fracturing Plugging removal makes it easy for the injected water to channel along the direction of the main fractures, resulting in early water breakthrough in the production wells in the direction of the main fractures and poor water flooding. Prominent problems such as excessively high liquid water cut, poor water flooding sweep, and low recovery degree

[0006] (2) Due to the high wax precipitation point of crude oil, when the bottom hole temperature drops to the wax precipitation point, wax crystals will precipitate and adhere to the wellbore wall, resulting in serious wax deposition in the wellbore

The disadvantage of this method is that since the vertical distance between the vertical gas injection well and the horizontal production well is only 5-10 meters, high-temperature air and combustion fronts can easily enter the horizontal production well at the bottom of the gas injection well during the field implementation process, thereby There is a serious explosion hazard problem, and the application does not mention what operational measures to avoid the safety hazard problem

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