SU929820A1 - Method of thermal-mine working of oil deposit - Google Patents

Description

(54) METHOD FOR HEAT AND MINE DEVELOPMENT OF OIL FIELD

one

The invention relates to the oil industry, in particular, to methods of thermo-mining of oil fields.

The known method of thermo-mining oil fields development consists in heating the formation by pumping through a system of injection wells, drilled supra-formation mining workings of a heat-transfer agent (steam), and extracting oil from production wells located in the lower part of the productive formation 1.

The method is not effective enough because of the incomplete coverage of the reservoir effect.

There is also known a method of thermo-mining development of an oil field by cyclically pumping heat-transfer agent (steam) and cyclically withdrawing oil from the reservoir through the injection and production wells divided into groups, and together with steam they inject alkali 2.

The disadvantage of this method is the low coverage of the formation with the displacement at a rare grid of wells, when the wells are drilled from the surface of the earth. When the well network is compacted, the displacement coverage rate increases, and drilling costs do not increase. At a certain ratio of the density of the grid of wells and the depth of the process, the process becomes ineffective.

5 The purpose of the invention is to increase the oil displacement ratio and the formation coverage of the formation.

This goal is achieved by the fact that one of the groups of injection wells, not, (j) continuously pumps a working agent that reduces surface tension at the boundary — oil-water and oil-rock.

At the same time, the wells into which the working agent is pumped, which reduces the tension surface, are placed through a row, and 15 in a row — at least through one injection well.

In addition, alkali is used as a working agent that reduces surface tension.

The method is carried out as follows.

Claims (2)

An aggregate of underground mine workings is created, including shaft shafts, near-shaft workings. drifts and working galleries. A drill of these working galleries injection and production wells. The injection and production wells are divided into groups. The coolant is supplied to the oil-bearing formation to heat it up to the temperature at which the oil acquires the necessary fluidity. For various oil fields, this temperature can vary considerably within 60-250 ° C and depends on the properties of the oil. A permanent injection of an aqueous solution of NaOH in an amount of 0.1-0.3 pore volume of the reservoir is carried out in one of the injection well groups. In this case, the concentration may be 0.001 wt. %, the amount of the injected solution of 0.3 pore volume of the reservoir. The injection wells for supplying an aqueous solution to the oil-bearing formation should be sufficient to cover the formation both in area and thickness, i.e. the grid of wells should be as uniform as possible. In the area of the well through which the formation is affected by the alkali solution, there must be several wells through which steam is injected. The well, into which the working agent is injected, reduces the surface tension, it is advisable to place it through a row, and into a row through one or several injection wells. Simultaneously with the injection of an aqueous solution of alkali into another group of wells, cyclical injection of a heat carrier (steam) is carried out with a duration of injection and stop periods of 10-30 days. The discharge pressure is from 1–20 kg / cm 2. In the particular case of the duration of steam injection and shutdown can be 15 days each, the discharge pressure is 3 kgf / cm. Oil extraction from production wells is carried out cyclically in such a way as to change the direction of filtration streams of the alkali solution rim. Oil is supplied from the working gallery through the mine workings to the surface. Thus, the injection of an alkali solution permits an additional 31.6 thousand tons of oil to be extracted from each million balance reserves of oil with additional costs 1.5 times less than with steam injection. The specific steam consumption during the application of the proposed method decreases from 2.6 to 2.4 t / t. 1. Thermal development method for oil field development by cyclic injection of coolant into the formation and cyclic recovery of oil from the formation through injection and production wells, divided into groups, characterized in that in order to increase the oil displacement factor to the formation coverage by one from the groups of injection wells, a working agent is continuously pumped in to reduce the surface tension at the boundary — oil-water and oil-rock. 2. A method according to claim 1, characterized in that the wells into which the working agent is pumped, which reduces the surface tension, are placed through a row, and into a row through at least one injection well. 3. Method according to paragraphs. 1 and 2, characterized in that an alkali is used as a working agent for reducing the surface tension. Sources of information taken into account in the examination 1. USSR author's certificate number 468529, cl. E 2 B 43/24, 1974. 2. US patent number 3732926, cl. 166-272, 1973 (prototype).