RU2394152C1 - Procedure for repair of production wells - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: procedure consists in implementation of hydro-jack block mounted of wellhead after disassembly of production tree to main gate, whereupon main gate is removed from tubing string head by means of hydro-jack bock. Further, the hydro-jack block is connected to flow string; the flow string is stretched; a control head is connected to the flow string; the control head and the suspended flow string are installed in the production well; and the tubing string head is dismantled.

EFFECT: reduced labour intensiveness and increased efficiency, also reduced idle time of well and elimination of unfavourable results of operation related to production horizon, absence of leaks of well medium to atmosphere.

7 dwg

Description

The invention relates to the oil and gas and exploration industries and is intended for the production of work on the repair of wellhead equipment or its replacement.

During the operation of wells due to various reasons (poor initial installation, misalignment of the wellhead of the casing strings, prolonged exposure to aggressive and toxic components of the wellbore environment, etc.), the sealing elements of the wellhead suspension of the string of the tubing string, tubing head and as a result, the appearance of high annular and intercolumn pressures. Corrosion also occurs with a violation of the tightness of the flange connections of the pipe head, fountain fittings (FA), with the appearance of gaps in their flange connections and leakage of the borehole medium into the atmosphere. These and other malfunctions are identified during inspections and audits of wellhead equipment. Depending on the degree of technical condition of the faulty wells, a plan for their capital (current) repair is drawn up.

The requirements and scope of work on the overhaul and current repair of wells are established by the regulatory document of Gazprom, which sets out the procedure for a set of measures to prepare for repair, repair and commissioning of wells after repair (1).

Repair of a production well is carried out with the help of mechanized units for repair of A-50 or Azinmash type wells with the preparation of a special working area for them, as well as special lifting and transport vehicles, cementing units, it requires significant material and technical costs for preparation, storage and injection filling fluid. Silencing a well causes it to stop functioning for a rather long period of time with possible unpredictable complications and adverse consequences due to the impact on the productive horizon.

“Production and scientific organizations are allowed to use the new technologies developed by them for overhaul, current and underground well repairs that do not contradict safety rules in the oil and gas industry. With the repeated use of the developed new technologies (3 or more times), in addition to the work plan, the developer organization is obliged to develop and agree on the regulations for the conduct and all the necessary instructions for the types of work ”(1, p. 7, p. 4.15).

The aim of the invention is to reduce labor costs, increase labor productivity, increase the degree of safety of working personnel when carrying out repair work to replace wellhead equipment, as well as reduce the downtime of the well and eliminate the adverse effects of its operation associated with exposure to the productive horizon.

This goal is achieved in that the repair of production wells, due to the need to replace the wellhead equipment, or its individual faulty elements, is carried out in a manner characterized in that they use a hydraulic jack that is installed on the wellhead after dismantling the fountain valves to the main valve, and then using the hydraulic jack block is removed from the tube head of the main valve, connect the hydraulic jack to the tubing string, tension it, connect to the column N T wellhead device mounted device wellhead with the tubing hanging in the production string and produce a tubing head disassembly.

Figure 1 shows a hydraulic jack installed on the mouth of the emergency well after dismantling the FA to the main valve; figure 2 - removal from the pipe head of the main valve with a transition flange (adapter); figure 3 - connecting the hydraulic jack to the tubing string; figure 4 - tension of the tubing string for dismantling the tubing suspension assembly; figure 5 - connection to the tubing string of the wellhead device for sealing and holding the tubing string (hereinafter referred to as the device); figure 6 - installation of the wellhead device with a suspended tubing string in the production string; figure 7 - dismantling of the pipe head of the well.

Work on well repair, due to the need to replace faulty elements of wellhead equipment using a hydraulic jack unit (hereinafter referred to as HDB), is carried out in the following order.

Preparatory work is being carried out at the well: a blind plug (packer) is installed, a circulation valve is opened, the over-packer part is filled with liquid and pressed by pressure, thereby providing two protective barriers, the presence of which allows high-risk work. After verifying the tightness of the packer, dismantle the piping of the well and the tree FA to the main valve (figure 1).

After the delivery of the hydraulic cylinder to the place of work, two of its working hydraulic cylinders 1 are dismantled from the base and, using special support brackets 2, are mounted on the flange connection of the casing 3 and pipe 4 of the well heads. By means of special wedge pins 5 and supporting brackets 6, the hydraulic cylinders 1 are mounted strictly vertically, the beam 7 is mounted on the upper ends of their rods and fastened with nuts 8. A hydraulic-controlled slip-type coil 9 (hereinafter referred to as HQ) is mounted on the beam, and a lifting cracker is passed through it and clamped pipe 10 with nipple threads at the ends. A flange 11 of the same size as the flange of the main valve 12 is screwed onto the lower threaded end, and a sleeve 13, into which the ball valve 14 is screwed, is screwed onto the upper one.

Having released the crackers SHK (figure 2), lower the lifting pipe 10 and connect the flange 11 to the flange of the main valve 12. The connecting studs of the transitional flange 15 and the pipe head 16 are removed, clamp the pipe 10 with the crackers of the ShK, then the hydraulic valve 1 tear off the main valve with the flange 15 from the pipe head 16 and lift it to a distance L, sufficient for the smooth dismantling of the valve. After removing the valve from the pipe 10, unscrew the flange 11.

Having released the crackers SHK (figure 3), lower the pipe 10 into the pipe head 16 until the threaded part of the pipe stops in the wellhead suspension 17 of the tubing string 18 and wrap it in the thread of the suspension.

Clamp the crackers with a barbecue pipe 10 (figure 4) and hydraulic cylinders 1 HDB raise the tubing string 18 to a distance H from the wellhead suspension 17 to the flange, sufficient for installation on the mating end of the pipe head 16 of the clamp special pipe 19 (hereinafter referred to as XST), which clamp the column, thereby unloading its weight on the column head 3, after which the wellhead suspension is disassembled and dismantled.

The hydraulic cylinders 1 (Fig. 5) raise the beam 7, between the pipe 10 and the tubing string 18, the wellhead packer 20 is installed, then the HCT is dismantled.

Clutching breadcrumbs HQ 9 pipe 10 (Fig.6), lower the tubing string into the well, providing the entrance of the packer unit 21 of the packer 20 into the production casing 22 at the designated distance h. Having connected the pressure hose to the nozzle A from the hydraulic power station (from the hand pump) and supplied with it the working fluid under pressure, the annular space is sealed by the packing unit 21 and the packer is connected to the production string by the anchor unit 23. After that, the unions A and B. are unscrewed.

From the packer 20 (Fig.7) disconnect the pipe 10 and dismantle it together with the HQ 9 from the yoke 7, after which, by hanging slings 24 to it, dismantle the pipe head 16.

After revising the disassembled units and parts of the wellhead equipment, eliminating the identified malfunctions (if necessary, replacing the defective elements with new ones), they are mounted in the reverse order, while the packer and anchor nodes of the wellhead packer are brought back to the initial position by applying pressure to the packer nozzle B ( 6).

Information sources

1. OJSC Gazprom, the standard of the organization “Unified Rules for Repair Work in the Wells of OJSC Gazprom RD 21-140-2005”, LLC IRTs Gazprom, Moscow, 2005.

2. Patent for invention No. 2215116 "Hydrojack unit", Moscow, 10.27.2003

Claims (1)

A method of repairing production wells, due to the need to replace wellhead equipment or its individual faulty elements, characterized in that they use a hydraulic jack, which is installed on the wellhead after dismantling the fountain valves to the main valve, after which the main valve is removed from the pipe head using a hydraulic jack connect the hydraulic jack to the tubing string, tension it, connect the wellhead device to the tubing string, install the mouth howl with a suspended tubing string in the production string and dismantle the pipe head.

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