CN107542423A - A kind of sieve tube completion horizontal well expansion sleeve pipe shutoff method - Google Patents

Abstract

The present invention relates to a water plugging method of screen pipe completion horizontal well expansion casing. Firstly, determine the position 3 of the outlet water body of the horizontal well; Blocking agent 4; then, expand the expansion sleeve 5 to achieve mechanical support for the chemical blocking agent; the expansion sleeve string includes the expansion sleeve 5, the expansion cone 6 and the expansion starter 7. The invention adopts the expansion casing to mechanically support the chemical plugging agent, which can avoid the defect of the conventional chemical water plugging method that the plugging agent is pressed back into the wellbore in a short time to cause water plugging failure, and at the same time, the expansion casing is used as the mechanical support to lose the inner diameter of the wellbore Small in size, simple in process and can be implemented in stages, it can be widely used in fields such as screen completion, horizontal well water plugging and the like.

Description

Water plugging method of expansion casing in horizontal well with screen completion

technical field

The invention relates to the technical field of drilling and completion in the petroleum and natural gas industry, and provides an operation method for water plugging of screen tube completion and horizontal wells.

Background technique

Horizontal wells increase the drainage area of production layers, and can develop reservoirs under low production pressure differentials. They have become an important technical means to speed up production capacity construction, improve oil recovery efficiency, and increase recoverable reserves. Widely used in medium and high permeability, heavy oil and low permeability reservoirs. However, affected by cost and technical factors, horizontal wells at home and abroad mainly adopt the slotted liner completion method without packers outside the pipe. This kind of completion method accounts for 70% in China and 90% in foreign countries. There are two main methods of water output from horizontal wells: bottom water coning and fracture intrusion. Due to the special well structure of horizontal wells, if no measures are taken after water breakthrough in horizontal wells, the water cut will continue to rise, seriously restricting its overall development effect.

There are two main water plugging methods for horizontal well completion with screen tube completion: general plugging agent injection method and annulus isolation positioning injection method. These two methods have their limitations. The general plugging agent injection method: the chemical plugging agent will be quickly pressed back into the wellbore under the action of pressure difference. Annulus separation positioning injection method: the construction process is complicated, and the inner diameter loss is large after water blocking. Patent CN201420691031 provides a horizontal well water plugging packer, which is composed of an upper joint, a rubber tube, a central pipe, a locking part, slips, and a hydraulic setting part, and the outer tube of the central pipe between the upper joint and the rubber tube A centralizing device is installed on the wall, and the centralizing device includes at least three groups of centralizing bodies. When setting the packer, through the function of the centralizing device and the slips, it is positioned with the center of the casing and the rubber tube is evenly released along the circumference, realizing long-term effective setting in the horizontal well section, and the rubber tube can be evenly distributed along the circumference during setting. release to realize water finding and water blocking in horizontal wells, but there are problems of difficult construction, poor stability and reliability. Generally speaking, at present, there is no effective method at home and abroad for the water production of screen completion horizontal wells.

Contents of the invention

The purpose of the present invention is to provide a more reliable technical method, lower operating price, simple and efficient water plugging method for screen tube completion horizontal well expansion casing for the current problem of screen tube completion horizontal well water output.

The present invention is achieved like this:

A water plugging method for screen completion horizontal well expansion casing, firstly, determine the position of the water body 3 of the horizontal well; then, by sending the drilling tool 8 into the expansion casing string, inject the chemical plugging agent 4 at the position of the determined water body 3 Then, expand the expansion sleeve 5 to achieve mechanical support for the chemical blocking agent; the expansion sleeve string includes the expansion sleeve 5, the expansion cone 6 and the expansion starter 7.

The above program also includes:

The chemical plugging agent 4 is squeezed and injected into the formation in sections according to the position of the water body 3 during the running of the expansion casing 5 strings.

Before the expansion casing 5 goes into the well, a section of the sealing rubber tube 9 is pre-vulcanized before and after the expansion casing 5 strings, or before the expansion casing 5 goes into the well, a section of the sealing rubber tube 9 is respectively set on the upper and lower walls of the expansion casing 5 in advance.

The expansion sleeve 5 is plastically deformed at the design position, making the expansion sleeve a permanent support for the chemical plugging agent, ensuring that the chemical plugging agent will not be pushed back into the wellbore by the pressure difference, thereby ensuring long-term effectiveness of water plugging.

The advantages of the present invention are:

(1) The expansion casing can provide a long-term mechanical support for the chemical plugging agent, so that the chemical plugging agent can continue to function and greatly improve the service life of the horizontal well.

(2) Compared with other water blocking methods, the inner diameter loss is the smallest.

(3) Segmented plugging can be carried out for different water outlet levels.

(4) Relatively speaking, it has simpler process and lower cost.

Description of drawings

Figure 1 is a schematic diagram of finding and determining the water outlet position in the method of the present invention;

Fig. 2 is a schematic diagram of lowering expansion casing strings and squeezing chemical plugging agent in the method of the present invention;

Fig. 3 is a schematic diagram of the expansion of the expansion casing to complete the water shutoff operation in the method of the present invention.

In the figure: 1. Completion casing, 2. Screen pipe, 3. Water body, 4. Chemical plugging agent, 5. Expansion casing, 6. Expansion cone, 7. Expansion starter, 8. Sending into drilling tool, 9 .Sealing rubber cartridge.

detailed description

Now in conjunction with the accompanying drawings of the description, the present invention will be further described.

As shown in Figures 1 to 3, a water plugging method for screen tube completion horizontal well expansion casing is to discover the water outlet of the horizontal well and determine the water outlet point 3, then run the expansion casing string combination and inject chemical plugging at the water outlet point. agent 4, continue to run down the expansion sleeve 5 to a predetermined position to expand the expansion sleeve 5, and make the expansion sleeve 5 a permanent support operation of the chemical blocking agent 4.

As shown in Fig. 1, for the water discharge in the production process of a horizontal well completed with completion casing 1 and screen 2, it should first be determined as point water discharge or bottom water coning, and the position of water body 3 should be determined after testing.

As shown in Figure 2, according to the design requirements, the expansion casing string is lowered. The expansion casing string includes the expansion cone 6, the expansion starter 7, and the expansion casing 5. The upper and lower ends of the expansion casing string are vulcanized with sealant rubber cylinders 9.

During the run-in process, the chemical plugging agent 4 can be injected into the stratum by sending the drilling tool 8 at different positions according to the position of the water body 3. After the injection of the chemical plugging agent 4 is completed, the expansion casing 5 strings are lowered to the designed position.

As shown in Fig. 3, after the expansion casing string is lowered to the designed position, the expansion operation of the expansion casing 5 is carried out by feeding the drilling tool 8 and pumping the working fluid until all the expansion casing 5 is expanded, providing chemical plugging agent 4 Reliable mechanical support and restoration of wellbore access.

The present invention adopts the operation method of squeezing the chemical plugging agent 4 while running in the expansion casing in series, and can selectively squeeze the chemical plugging agent 4 in sections, and at the same time, the expansion casing 5 can provide reliable protection for the chemical plugging agent 4 after expansion. Mechanical support prevents the chemical plugging agent 4 from being pressed back into the wellbore in a short period of time to cause water plugging failure, which greatly improves the reliability of water plugging in horizontal well completions with screens, and can be widely used in fields such as water plugging in horizontal wells with screen completions.

Claims (5)

1. A method for water plugging of screen pipe completion horizontal well expansion casing, characterized in that: Firstly, determine the position of the horizontal well outlet water body (3); then, run the expansion casing string through the drilling tool (8), and inject the chemical plugging agent (4) at the position of the determined water body (3); then, place the expansion casing (5) Expansion to achieve mechanical support for the chemical blocking agent; the expansion sleeve string includes expansion sleeves (5), expansion cones (6) and expansion starters (7). 2. The water plugging method of expansion casing for horizontal well completion with screen tube according to claim 1, characterized in that: the chemical plugging agent (4) is inserted into the expansion casing (5) according to the position of the water body (3) Squeezed into the formation in the middle segment. 3. The water plugging method of expansion casing for horizontal well completion with screen tubes according to claim 2, characterized in that: before the expansion casing (5) enters the well, a section of sealant is pre-vulcanized before and after the expansion casing (5) Barrel (9). 4. The water plugging method of expansion casing for horizontal well completion with screen tubes according to claim 2, characterized in that: before the expansion casing (5) enters the well, a section is placed on the upper and lower outer walls of the expansion casing (5) in advance Sealant cartridge (9). 5. The method for water plugging with expansion casing for horizontal well completion with screen tubes according to any one of claims 1-5, characterized in that: the expansion of the expansion casing (5) is plastic deformation.