RU2011791C1 - Process of running of sea oil-and-gas field and device for its realization - Google Patents

Abstract

FIELD: production of oil and gas on sea shelf, mainly under ice conditions. SUBSTANCE: device includes casing string with extension piece and means for shutting off of string manufactured in the form of nonreturn rotary clack valve tightly coupled with extension piece over length of its entry into body of clack valve corresponding to its full opening. For creation of moment of turn of clack valve and for its holding in closed position clack valve is provided with weight installed outside body. With worsening of ice condition extension piece is screwed out of device and casing string is tightly shut off. For resumption of running extension piece is screwed into shutting off device with effort exceeding that of its shutting off. EFFECT: enhanced operational reliability and safety. 2 cl, 1 dwg

Description

 The invention is intended for the operation of offshore oil and gas fields, mainly in ice conditions. If the ice situation worsens or stormy conditions require the rig to leave the place of work, the corking of the well is carried out by pouring cement mortar into it followed by drilling cement plugs when resuming work (V. Korobkov et al. Underwater technology, L., Shipbuilding, 1981, p. 109). Such blocking and opening operations require a lot of labor and time.

 The proposed method aims to reduce labor costs and time to complete these operations.

 This goal is achieved by the fact that the opening and closing of the wellhead is carried out automatically with the help of a disk-shaped blocking body, into which the casing extension cord is screwed (unscrewed) simultaneously with its assembly (disassembly), and the extension screwing force into the blocking body is greater than the closing force the most overlapping organ.

 Known overlapping device includes a sealed enclosure and a non-returning shut-off element, triggered by the flow of a conducted medium.

 The goal is to ensure the forced opening of the locking element during mechanical action of the screwed part of the casing extension on it.

 The goal is achieved by the fact that the device for implementing this method includes a casing with an extension and a disk-shaped blocking assembly that is configured to interact with the extension of the casing along the length of its entry into the blocking block.

 The significance of the differences in the proposed solution lies in the exclusion of labor-intensive operations for the injection of cement into the well and its removal.

 The drawing shows a device for shutting off a well.

 The claimed method of operating offshore oil and gas fields in ice conditions is carried out in the following sequence of operations.

 A well is drilled in which a casing 2 is placed during the drilling process, and a device 1 for shutting off the well of automatic action is placed at its end. The upper part of the column (extension cord) 3 is screwed into this device, through which oil (gas) is taken from the well.

 When the ice situation worsens or stormy conditions, the extension cord is turned out of the device 1, while automatically closing the casing 2 hermetically. When work is resumed, the extension cord 3 is again screwed into the device 1 to close the well with a force exceeding the closing force of its shut-off element, setting it automatically to " open "wells.

 The method allows to exclude emergency situations (the effect of ice on the drilling rig, damage to the casing), as well as reduce the amount of work when resuming operation of the well.

 A device for implementing this method includes a casing pipe 2 located in the well, its upper part (extension) 3 and a locking unit permanently installed at the junction of the extension with pipe 2 in the form of an irrevocable poppet shut of automatic action.

 A rotary disk 5 with a mechanical seal 10 is installed on the shaft housing 6 on the shaft 6, and a load 7 is installed on the shaft outside the housing, reliably pressing the valve plate against the coaming 4. Outside of the coaming, a threaded cup 8 with a seal 9 is installed, into which the casing extension 4 is tightly screwed. columns interacting with the plate along the length of its entry into the clap.

 PRI me R. When changing the ice situation or other conditions when it is necessary to take the rig out of operation and block the well, do the following: unscrew the extension 3 from the cup 8 of the flap, while its end, even before leaving the seal 9, releases the clap plate 5, which under the action of the load 7 tightly pressed against coaming 4, blocking the oil and gas output (under their pressure, the plate is additionally pressed against coaming). When resuming operation, the extension cord 3 is inserted into the cup 8 and is screwed in to provide an axial force exceeding the clamping force of the clapper plate 5 against the coaming 4. In this case, the extension cord 3 opens its end and enters the clap body by the value corresponding to its full length discovery.

 Using the proposed solution will improve the efficiency of oil and gas fields in the northern seas, the safety of work and reduce costs.

Claims (2)

 1. A method of operating offshore oil and gas fields, including periodic closure of the wellhead, characterized in that the pipe string is equipped with an extension cord and a disk-shaped rotary blocking body, and the mouth is opened and closed by screwing and unscrewing the column extension into the disk-shaped blocking body, while creating a screwing force, exceeding closing force of the overlapping body.  2. A device for operating offshore oil and gas fields, including a casing pipe and a disk-mounted rotary blocking unit with a drive installed inside the pipe, characterized in that the drive is made in the form of a load mounted outside the pipe, and the casing extension is installed with the possibility of interaction with the blocking unit for a length call at the last.

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