RU2234597C1 - Method for horizontal oil well bore operation and making - Google Patents

Abstract

FIELD: oil industry, particularly oil well bore operation and making in oil beds with areas absorbing drilling mud.

SUBSTANCE: method involves making well bore along with exposing area of full drilling mud escape; stopping drilling process; continuing drilling process and operating well. After stopping borehole drilling well operation is carried out up to reduction flow rate in well, up to reduction economic efficiency thereof or up to water invasion of ready product. Then area of drilling mud escape is isolated. After that elongated flexible tubes with down-hole motor and eccentric bit are deepened into well bore by coltubing and borehole making is continued up to reaching next drilling mud escape area or up to reaching another design point with flushing thereof with oil circulating in closed loop.

EFFECT: increased quality of oil bed exposing, maintaining collecting properties of oil bed.

2 ex

Description

The invention relates to the oil industry and may find application in the operation and wiring of a horizontal wellbore in oil reservoirs in which mud absorption zones are encountered.

A known method of drilling with stopping the process of deepening wells to isolate the absorption zone (Temporary instructions for the study of absorbing formations and the fight against absorption of drilling fluid during drilling. - M .: VNIIKRneft, 1974, p. 93-95).

However, this method is not suitable for cases when the absorption zone of the drilling fluid is opened in the oil reservoir, since its isolation leads to a decrease in the flow rate of the well.

The closest technical solution to the claimed is a method of constructing wells of a multilayer oil field, including drilling a well to the design depth, lowering the production casing and cementing it. After opening the first oil reservoir by drilling, the well is fixed. Further, the drilling of the well continues with a bit of smaller diameter, revealing the remaining productive formations with subsequent cementing of the drilled part of the well. The last tubing shank pipes extending opposite the first oil reservoir are selected from easily drilled material, for example fiberglass. In this case, before the cementing of the well, a disconnector is installed opposite the producing formation, lowered into the well as a part of the casing, followed by cementing of the separated part of the well below and above the disconnector (RF patent No. 2161239, class E 21 B 33/13, publ. 2000 - prototype).

The disadvantage of this method is that when an open absorption zone with extremely high permeability, called the zone of complete drilling mud withdrawal, the drilling process becomes uncontrollable due to the difficulty of monitoring the drilling fluid withdrawal. Drilling fluid penetrates into the formation to a considerable depth, worsens reservoir properties. As a result, after completion of drilling, the well is put into operation with a low oil production rate. Its operation is delayed for a long time, which is associated with an increased cost of its maintenance.

The objective of the invention is to improve the quality of the opening of the oil reservoir and the preservation of its reservoir properties.

The problem is solved in that in the method of operating and wiring a horizontal wellbore of an oil well, including wiring a well with opening a zone of complete drilling mud cutoff, stopping wiring, continuing wiring and operating the well, while stopping the wiring, the wells are operated until profitability or flooding of produced products is achieved isolate the zone of complete drilling mud drift, use long coiled tubing with a downhole motor and an eccentric bit, etc. wiring extends up to the next full withdrawal zone mud or design point with flushing oil by its closed-loop circulation.

The features of the invention are:

1. the wiring of the barrel with the opening of the zone of complete care of the drilling fluid;

2. stopping the wiring;

3. continued wiring;

4. well operation;

5. when stopping the wiring operation of the well to achieve unprofitability or flooding of produced products;

6. isolation of the complete drilling mud care zone;

7. descent using the installation of coiled tubing of long flexible pipes with a downhole motor and an eccentric bit;

8. continuation of wiring to the next zone of complete drilling mud clearance or design point;

9. the same with oil flushing;

10. the same for a closed cycle of oil circulation.

Signs 1 to 4 are similar to the prototype, signs 5 to 9 are essential distinguishing features of the invention.

SUMMARY OF THE INVENTION

During the operation and wiring of the horizontal wellbore, it is far from always possible to ensure the quality of opening and maintain the reservoir properties of the bottomhole zone of the well.

The objective of the invention is to improve the quality of the opening of the oil reservoir and the preservation of its reservoir properties.

To do this, conduct horizontal wiring with the opening of the complete drilling mud care zone and stopping the wiring. When the wiring is stopped, the wells are operated until the water is extracted from the produced product or its flow rate is reduced to the level of unprofitability. Long coiled tubing with a downhole motor and an eccentric bit are lowered using the coiled tubing unit and continue to the next zone of complete drilling mud departure or design point with oil flushing in a closed cycle of its circulation.

Due to the technological suspension of the deepening (continued drilling) of the horizontal well, it becomes possible to maintain the integrity of the reservoir properties of the exposed oil reservoir and to operate it with a maximum flow rate until it is reduced and to use the produced oil as a flushing fluid while continuing to drill the horizontal well to the design point using long flexible pipes ( coiled tubing) with a downhole motor and an eccentric bit.

The claimed method is as follows.

The well is drilled according to the standard scheme. First, the upper part of the geological section is cased, then an open horizontal trunk is drilled in the oil reservoir. After opening the absorption zone, i.e. complete care of the drilling fluid in the oil reservoir, drilling is stopped. The rig is removed from the well. The well is being commissioned. After reducing the production rate of the extracted oil until unprofitability or flooding of the produced products is achieved, the zone of complete drilling mud withdrawal is isolated. An installation with flexible long pipes (coiled tubing) is installed at the well site. A downhole motor with an eccentric bit is lowered into the well. A working agent is pumped through flexible long pipes (coiled tubing), thereby driving a downhole motor and an eccentric bit. They create a circular circulation in a closed (closed) cycle of the produced oil and drill a horizontal well to the next zone of complete drilling mud withdrawal or to the design point.

Case Studies

Example 1. Drill a well with a depth of 1000 m to the top of the reservoir and casing string. A horizontal well is drilled from it along an oil reservoir 100 m long. At the same time, a zone of complete drilling mud removal is opened. Design waste length of 300 m. Further drilling without drilling mud coming to the surface is impractical because this leads to contamination of the formation and costly losses of a large volume of drilling fluid.

A drilling rig is removed from the well. The well is put into operation. The wells continue to operate with a maximum production rate of 1 year before watering the produced products. Isolate the complete drilling mud care zone. A coiled tubing installation is located at the well site — an installation with long flexible pipes. A downhole screw motor with an eccentric bit is lowered into the well. Restore circular circulation with oil washing. Drilling is carried out according to known technology with backpressure on the absorption zone equal to the reservoir pressure. In the well, the formation is opened with a horizontal wellbore over the entire previously planned length. The well is put into operation with increased production rate with girth drainage of a new section of the oil reservoir.

As a result, it is possible to increase well production by 20%, which indicates the quality of the opening of the oil reservoir and the preservation of its reservoir properties.

Example 2. Perform as example 1. In the case of a re-detection of the zone of complete care of the drilling fluid repeat the operations of oil selection and drilling using the coiled tubing.

Application of the proposed method will improve the quality of the opening of the oil reservoir and maintain its reservoir properties.

Claims (1)

A method of operating and wiring a horizontal wellbore of an oil well, including wiring the well with opening the complete drilling mud care zone, stopping the wiring, continuing wiring and operating the well, and when the wiring is stopped, the wells are operated until profitability or flooding of the produced products is achieved, isolate the complete mud care zone , with the help of the coiled tubing installation, run long flexible pipes with a downhole motor and an eccentric bit and continue wiring to the next minutes complete withdrawal zone mud or design point with flushing oil by its closed-loop circulation.