CN206397473U - A kind of open hole well wall cake scraping tools - Google Patents

Abstract

The utility model relates to a well wall mud cake scraping tool for an open well. The technical solution is: the rigid centralizer sub-joint, the mud cake scraping steel wire sub-joint, and the ball centralizer sub-joint are independent structures, which can be combined and connected freely through threads; the inner diameter of the tool is consistent with the inner diameter of the completion casing, and the upper The joint and the lower joint are connected with the casing; the mud cake scrapes the short joint of the steel wire, and it is an interference fit with the wellbore. The steel wires are arranged in a straight line, and the circulating fluid can flow through the channels between the rows of steel wires. The beneficial effects are: ①The interference fit between the steel wire and the well wall can effectively destroy the mud cake structure; ②There are rigid centralizers and ball centralizers on the upper and lower sides of the tool to ensure the centering of the casing at the tool; ③The flow channel structure of the tool ensures fluid circulation. In a word, the utility model can not only realize the effective removal of irregular wellbore mud cake, but also ensure the normal circulation of mud, flushing fluid, cement slurry and other well fluids, thereby improving the mud cake flushing efficiency and increasing the bonding strength of the cementing interface.

Description

Well wall mud cake scraping tool for open hole

technical field

The utility model relates to a petroleum well completion tool, in particular to a well wall mud cake scraping tool for open hole wells.

Background technique

Mud cake is a solid phase deposit deposited on the well wall or formation during the drilling fluid filtration process. This deposit is conducive to balancing the bottom hole pressure during the drilling process, has certain lubricity, and can play a safe and fast The role of drilling. However, when the casing or open hole is completed, the formed mud cake not only blocks the oil and gas pore channels in the formation, but also forms a barrier inside the wellbore, thereby reducing the bonding strength between the cement stone and the formation, which is not conducive to the improvement of cementing quality .

Clearing the drilling fluid mud cake of oil and water wells is an important work related to displacement efficiency and cementing quality. At present, the common method is to use prefluid (or flushing fluid) to flush the mud cake. The flushing fluid is a certain amount of fluid that is pumped in advance before grouting to flush the mud cake attached to the well wall and casing wall. However, the effect of the flushing fluid is limited, and it can only flush the virtual mud cake on the surface in the process of natural flow, and cannot damage the entire mud cake structure; in comparison, auxiliary mechanical methods can effectively destroy the mud cake structure, and the mud cake The clearing effect will be more obvious.

For vertical wells, the scraping steel wire acts directly on the well wall without adding centralizers; for extended-reach wells and horizontal wells, under the action of its own weight, the casing clings to the lower edge of the well wall, and is stabilized by rigid centralizers and ball balls. The device can effectively ensure the centering of the casing, and prevent the scraping steel wire from losing its effect due to the compression of the casing weight.

An improved method of scraper and scraper (patent number: 201510985361.0), a composite scraper (patent number: 201310298346.X), a mud scraper for the inner wall of oil casing (201620144797.7) are all It is a scraper related to the casing, which is used in the fields of oil well completion and testing. It has the characteristics of simple structure, reliable operation and wide application range, but it does not have the function of scraping mud cake under naked eye conditions. The horizontal well mud cake cleaner (patent number: 201020252435.2) is used in conjunction with other sand control tools to complete extrusion or cyclic filling of sand control, slurry replacement and acidification of open hole horizontal wells, perforated horizontal wells, inclined wells, and vertical wells. It is widely used in the supporting downhole technology of sand control operations in oil production wells, and it does not have the ability to scrape mud cake under open hole conditions.

The wellbore mudcake scraping tool for open hole wells needs to achieve the function of scraping the wellbore mudcake during the well completion operation, and the technical requirements are also higher in terms of safety and feasibility. Its difficulties are mainly manifested in the following aspects:

① The tool must adapt to the complex wellbore conditions outside the pipe and meet the requirements for effectively scraping mud cake under this condition;

② Due to the need to apply extended reach wells and horizontal wells, it must have the function of casing straightening;

③ It must not affect the normal circulation cementing operation.

Utility model content

The purpose of this utility model is to aim at the above-mentioned defects existing in the prior art, and to provide a well wall mud cake scraping tool for open hole wells, which can not only realize the effective removal of irregular well hole mud cake, but also ensure that mud, flushing fluid, The well fluid such as cement slurry circulates normally, thereby improving the mud cake flushing efficiency and improving the bonding strength of the cementing interface.

The well wall mud cake scraping tool for open hole mentioned in the utility model includes an upper joint (1), a rigid centralizing body nipple (2), a mud cake scraping steel wire nipple (5), a ball centralizing body nipple section (7), lower joint (8), the upper joint (1) and the lower joint (8) are connected to the pipe, the rigid centralizer puppet (2), the mud cake scraping steel wire puppet (5), the ball centralizer The body pups (7) are independent structures, the internal diameter is consistent with the inner diameter of the casing, and are connected flexibly by screws. The lower part of the rigid centralizing body pup (2) is connected to the mud cake scraping steel wire pup (5) , the lower end of the mud cake scraping steel wire nipple (5) is connected to the ball centralizer nipple (7); the mud cake scraping steel wire nipple (5) is in interference fit with the borehole, and the mud cake scraping steel wire short The steel wires on the outside of the section (5) are arranged in a straight line, and the circulating fluid can flow through the channels between the rows of steel wires.

Preferably, a plurality of spiral centralizing strips (3) are provided on the outer side of the above-mentioned rigid centralizing body subsection (2), and the outer diameter of the spiral centralizing strips (3) is lower than the steel wire of the mud cake scraping wire subsection (5) The outer diameter of the spiral centralizing strips (3) is a liquid passage (4).

Preferably, the above-mentioned spiral centralizing strips (3) are arranged at 30°.

Preferably, a ball (6) is provided outside the middle of the above-mentioned ball centralizer pup joint (7), and the outer diameter of the ball (6) is lower than the outer diameter of the steel wire of the mud cake scraping wire pup joint (5).

Preferably, a plurality of ball seats are provided on the outside of the middle part of the ball centralizer short joint (7), and a plurality of balls (6) are arranged on the ball seats.

Preferably, three groups of steel wires are arranged in the longitudinal direction of the mud cake scraping steel wire pup (5), and each group of steel wires is formed by arranging 4-8 steel wires.

The beneficial effects of the utility model are as follows: ①The interference fit between the steel wire and the well wall can effectively destroy the mud cake structure; ②There are rigid centralizers and ball centralizers on the upper and lower sides of the tool to ensure the centering of the casing at the tool; The channel structure ensures the circulation of the fluid. In a word, the utility model can not only realize the effective removal of irregular wellbore mud cake, but also ensure the normal circulation of mud, flushing fluid, cement slurry and other well fluids, thereby improving the mud cake flushing efficiency and increasing the bonding strength of the cementing interface.

Description of drawings

Accompanying drawing 1 is the structural representation of the utility model;

Accompanying drawing 2 is the local enlargement diagram of the short joint of rigid centralizer;

Accompanying drawing 3 is the partial enlarged view of mud cake scraping steel wire nipple;

Accompanying drawing 4 is the local enlargement diagram of the short joint of the ball centralizer;

In the above figure: upper joint 1, rigid centralizer sub-joint 2, spiral centralizer strip 3, liquid passage 4, mud cake scraping steel wire sub-joint 5, ball 6, ball centralizer sub-joint 7, lower joint 8.

detailed description

The preferred embodiments of the present utility model are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described here are only used to illustrate and explain the present utility model, and are not intended to limit the present utility model.

Example 1, a well wall mud cake scraping tool for an open hole mentioned in the utility model, including an upper joint 1, a rigid centralizer sub-joint 2, a mud cake scraping steel wire sub-joint 5, and a ball centralizer sub-joint 7 , the lower joint 8, the upper joint 1 and the lower joint 8 are connected to the pipe, the rigid centralizer sub-joint 2, the mud cake scraping steel wire sub-joint 5, and the ball centralizer sub-joint 7 are independent structures respectively, and the internal diameter and sleeve The inner diameters of the pipes are the same, and they are movably connected by screws. The contact surface is provided with a sealing rubber ring; The lower end is connected to the ball centralizer nipple 7; the mud cake scraping steel wire nipple 5 is in interference fit with the wellbore, and the steel wires outside the mud cake scraping steel wire nipple 5 are arranged in a straight line, and the circulating fluid can pass through each row of steel wires channel flow between.

Among them, the outer side of the rigid centralizer short joint 2 is provided with a plurality of spiral centralizing strips 3, and the outer diameter of the spiral centralizing strips 3 is lower than the outer diameter of the steel wire of the mud cake scraping steel wire short joint 5; between the spiral centralizing strips 3 are The liquid passage 4; preferably, the above-mentioned spiral centralizing strips 3 are arranged at 30°.

In addition, a ball 6 is provided on the outside of the middle part of the above-mentioned ball centralizer short joint 7, and the outer diameter of the ball 6 is lower than the outer diameter of the steel wire of the mud cake scraping steel wire short joint 5; the above-mentioned ball centralizer short joint 7 A plurality of ball seats are arranged outside the middle part, and a plurality of balls 6 are arranged on the ball seats.

Preferably, three sets of steel wires are arranged in the longitudinal direction of the above-mentioned mud cake scraping steel wire nipple 5, and each set of steel wires is formed by arranging 4-8 steel wires.

The method for using the well wall mud cake scraping tool for the open hole mentioned in the utility model comprises the following steps:

During the construction process, the upper joint 1 and the lower joint 8 are normally connected with the completion casing, the rigid centralizer sub-joint 2, the mud cake scraping steel wire sub-joint 5, and the ball centralizer sub-joint 7 are combined according to the well conditions and technical requirements Completion string;

With the running of the completion string, when the completion string is run downhole and in place, circulation, cementing, displacement, and bumping are performed according to the cementing process; among them, the rigid centralizing body sub-joint 2 and the ball centralizing body sub-joint 7 plays a guiding role. The mud cake scrapes the steel wire short joint 5 to contact the well wall, and the protruding steel wire mechanically scrapes the well wall to change the attachment state of the original mud cake, which is convenient for mud, flushing fluid, and cement slurry in the later stage. The well fluid is used to flush the well wall and finally remove the mud cake.

The above descriptions are only some of the preferred embodiments of the present invention, and any person skilled in the art may modify the above-mentioned technical solutions or modify them into equivalent technical solutions. Therefore, any simple modification or equivalent replacement made according to the technical solution of the utility model belongs to the protection scope of the utility model.

Claims (6)

1. A wellbore mud cake scraping tool for an open hole, characterized by: including an upper joint (1), a rigid centralizer nipple (2), a mud cake scraping steel wire nipple (5), a ball centralizer nipple section (7), lower joint (8), the upper joint (1) and the lower joint (8) are connected to the pipe, the rigid centralizer puppet (2), the mud cake scraping steel wire puppet (5), the ball centralizer The body pups (7) are independent structures, the internal diameter is consistent with the inner diameter of the casing, and are connected flexibly by screws. The lower part of the rigid centralizing body pup (2) is connected to the mud cake scraping steel wire pup (5) , the lower end of the mud cake scraping steel wire nipple (5) is connected to the ball centralizer nipple (7); the mud cake scraping steel wire nipple (5) is in interference fit with the borehole, and the mud cake scraping steel wire short The steel wires on the outside of the section (5) are arranged in a straight line, and the circulating fluid can flow through the channels between the rows of steel wires. 2. The wellbore mud cake scraping tool for open hole according to claim 1, characterized in that: the outer side of the rigid centralizer nipple (2) is provided with a plurality of spiral centralizing strips (3), and the spiral centralizing The outer diameter of the bars (3) is lower than the outer diameter of the steel wire of the mud cake scraping steel wire nipple (5); there is a liquid passage (4) between the spiral centralizing bars (3). 3. The wellbore mudcake scraping tool for open hole according to claim 2, characterized in that: said spiral centralizing strips (3) are arranged at 30°. 4. The wellbore mud cake scraping tool for open hole according to claim 1, characterized in that: a ball (6) is provided on the outside of the middle part of the short joint (7) of the ball centralizer, and the place of the ball (6) is The outer diameter is lower than the outer diameter of the steel wire of the mud cake scraping wire pup joint (5). 5. The wellbore mud cake scraping tool for open hole according to claim 4, characterized in that: a plurality of ball seats are arranged on the outside of the middle part of the ball centralizer nipple (7), and the ball seats are arranged with Multiple balls (6). 6. The wellbore mud cake scraping tool for open hole according to claim 1, characterized in that: said mud cake scraping steel wire pup joint (5) is provided with three sets of steel wires in the longitudinal direction, and each set of steel wires consists of 4- 8 steel wires are arranged and formed.