US1520737A - Method of increasing oil extraction from oil-bearing strata - Google Patents

Description

Dec. 3 1 1,520,737

Y R. L, WREGHT METHOD OF INCREASING OIL EXTRACTION FROM OIL BEARING STRATA Filed April 26, 1924 INVENTQR.

Patented Dec. 30, 1924.

ROBERT L. WRIGHT, OF FORT DODGE, IOWA.

METHOD OF INCREASING OIL EXTRACTION FROM OIL-BEARING STRATA.

Application filed April 26, 1924. Serial No. 709,098.

To all whom it may concem:

Be it known that I, ROBERT L. VVRIGHT, a citizen of the United States,and a resident of Fort Dodge, county of \Vebster, and State of Iowa, have invented a new and useful Improvement in Methods of Increasing Oil Extraction from Oil-Bearing Strata,-of which the following is a specification, the principle of the invention being herein explained and the best mode in which I have contemplated applying that principle, so as to distinguish it from other inventions.

The present invention relates to a process for increasing the oil extraction from oil bearing strata, and more particularly to means for aiding the natural means by which oil is extracted. This is done. by altering or changing the conditions in the natural oil containing strata'so as to make them more favorable for the natural forces to move the oil from the containing strata into the well or chamber from which it may be pumped or withdrawn to the surface.

In extracting oil in its natural accumulation, the confined and absorbed gases are the principal agents in driving and carrying the oil from the poers or voids of the contain-- ing strata to the well. This action takes place, due to the reduction of the pressure 0 at the well casing allowing the gases .to move in this direction to carry and force the oil with the gas. The movement of the oil is resisted and retarded by the frictional resistance of the containing strata, and also by the inherent physical properties of the oil, and in some cases by the pressure exerted by a column of fluid standing in the well casing. The present invention assists these natural forces by forming artificial drainage channels from the well casing or from a chamber at the bottom thereof out into the oil bearing strata, these channels starting from a point below the strata and inclining upwardly and radially from the ca;- ing. In distinction to present methods, the gas and oil in the voids of the strata, do not have far to flow through the strata pores, most of which are of capillary size, i

'the gas into the sump. The channels of before reaching a channel of super capillary size, through which it will 'fiow freely by gravity. To further assist and increase-the amount of oil obtained, it is desirable to supply heat to the channels so as to tend to expand existing gas, to liberate more gas which is absorbed in the oil present in, the

oil bearing strata, and to volatilize some of the liquid hydrocarbons and thus increase the flow of both gas and oil. To the accomplishment of the foregoing and related ends, said invention, then, consists of the method hereinafter fully described and particularly pointed out in the claims.

The annexed drawing and the following description set forth in-detail one approved method of carrying out the invention, such disclosed method, however, constituting but one of the various ways in which the prin ciple of the invention may be used.

In said annexed drawing Fig. 1 is a diagrammatic vertical sectional view showing the general layout of the present invention; Fig. 2 is a diagrammatic horizontal section showing relative are-as reached; and Fig. 3 is a vertical section through the chamber, room and lower portion of the well casing.

In the drawing there is illustrated an oil well comprising the usual aperture 1, from the surface of the ground down through and into the oil bearing strata 30, and as shown in the drawing, this well or hole is extended below the oil bearing strata and is there enlarged into a chamber 2, the lower portion of which also acts as an oil sump 20. In the present invention this hole is made of considerable size, about 5 feet in diameter, large enough to receive a hollow shaft or well casing 3, this well casing being of sufiicient internal diameter to allow for elevator mechanism for access to the lower room and for the handling of necessary machinery. The casing is extended the full len h of the well or hole until it reaches thechamber at the bottom and is there pro vided with a room 4, which is sealed to the casing, but this room does not take up the entire space in the chamber. From the chamber are drilled several series of upwardly inclined channels 5, which extend radially from the chamber, and these chan- 1 nels are. extended up into and substantially through the oil bearing strata and form the drainage channels for the oil and each series are at a different-inclination and 10 the number of series will depend upon the area to be drained and the thickness of the .oil'bearing strata. In the casing is mounted an outlet ipe 6 for the gases, and this pipe is exten ed through the room into the chamber and thus into open communication with the channels so as to provide an escape tor the accumulated gases.

From the room are extended'a series ofheating pipes 7 which are run out into the channels, but which are smaller than the.

. able pipe 11, and which islikewise connected to an outflow oil pipe 12 extending up through the well casing. In using the heating pipes they may be either closed at the ends so as to form mere heating chambers which heat the oil strata by radiation from the pipe, or they may be perforated in certain instances to actually force steam out into the oil bearing strata to help vaporize and carry the oil back down the channels to the sump. Y

By the present proposed method a single well can be made to extract the oil from a very large ground area and it is particularly useful where the oil bearing strata is of the type which prevents the free flow of oil, or in such fields as where the wells must be driven close together in order to obtain the best results. It is also applicable to fields which have been partially exhausted, as the large casing may be placed in the middle of an oil bearing area and the laterals run out so as to tap many of the pockets throughout the oil bearing strata which do not naturally release the oil to a single small well hole of the usual type.

Other modes of applying the principle. of my invention may be employed instead of the one explained, change being made as regards the method herein disclosed, provided the step or steps stated by any of the following claims or the equivalent of such stated step or steps be employed.

I therefore particularly point out and distinctly claim as my invention 1. The method of increasing oil extraction from a well comprising the formation of a well casing extending below the oil containing strata forming a. chamber around from a well comprising the formation of a well casing extending below the oil containlng strata formlng a chamber around the bottom of said casing, running a series of radially extending channels laterally and inclined upwardly from said chamber into the oil bearing strata and supplying heat through said channels.

3. The method of increasing oil extraction from a well comprising the formation of a well casing extending below the oil containing strata forming a chamber around the end of said Casing to form a sump, drilling a series of laterally extending upwardly inclined channels from said chamber into the oil bearing strata, and pumping the accumulated oil from said sump.

4. The method of increasing oil extraction from a Well comprising the formation of a well casing extending below the oil containing strata forming a chamber around the end of said casing to form a sump, drilling a series of laterally extending upwardly inclined channels from said chamber into the oil bearing strata forming a closed room in said chamber and connected to said well casing, running a series of heating elements from said room out into such lateral channels, and pumping the accumulated oil from said sump.

The method of increasin oil extraction from a well comprising the i ormation of a well casing extending below the oil-containing strata forming a chamber around the end of said casing to form a sump, drilling a series of laterally-extending upwardly inclined channels from said chamber into the oil bearing strata, forming aclosed room in said chamber and connected to said well casing, running a series of heating elements from said room out into such lateral channels, pumping the accumulated oil from said sump and providing a gas outlet pipe in said well casing opening into said chamber.

'6. The method of increasing oil extraction from a well comprising the formation of a well casing extending below the oil containing strata forming a chamber around the end of said casing to form a sump, drilling a series of laterally extending upwardly inclined channels from said chamber into the oil bearing strata, forming a closed room in said chamber and connected to said well cas ing, running a series of heating pipes from said room into such channels, supplying a heating medium to said pipes, pumping the accumulated oil from said sump and providing a gas outlet pipe in said well easing opelh ing into said chamber.- I

Signed by me, this 26 day of March. i921.

ROBERT L. wmon'r.

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