The downhole choke
(57) Abstract:The invention relates to the oil and gas industry, in particular to the downhole equipment of oil and gas fields. Provides increased bandwidth for gas from the upper nadakarni layers in the scheme WEM well one string of tubing, prevents gas on the lower podvecerni at the top nadakarni layers when you stop well without her killing, prevents gas in the tubing when the renovations in the well when the pressure in this space against the throttle is greater than the pressure in the tubing. The inventive downhole choke placed on the tubing, includes a housing with apertures, a spring-loaded check valve and removable nozzle. The housing top and bottom are made connecting thread, with which it is attached directly to the tubing. The case is equipped with casing. Check valve and removable nozzle located in the annular gap between the casing and the casing. Inside the body is placed a sleeve with holes can be offset instrument cable technology for the SJ to the oil and gas industries, in particular, the downhole equipment of oil and gas fields, and can be used, for example, when the arrangement of wells under dual operation (DC) of two or more layers with different characteristics with the extraction fluid on one side of the column tubing, gas-lift method of extracting oil from the bottom prolific reservoir, during the development and killing the well reverse circulation etc.Known design downhole choke intended to regulate the mode of selection of the gas established by the instrument cable technology inside the tubing and consisting of a body and a removable nozzle with an inner diameter of providing a given mode of production fluid from the lower podvecerni layers .The disadvantages of the known designs is the inability to prevent flow of fluid from the lower reservoir into the upper nadakarni, as well as the inability to maintain a given mode of production fluid from the upper layers in the scheme WEM well on single Elevator tubing.Known downhole choke, selected as a prototype, is placed on the pump-compressometer installed instrument cable technology in a side pocket downhole camera - mandrel. The mandrel above and below has a mounting thread, with which it is mounted on the tubing and integral part of the design of the inductor is not. Check valve and removable nozzle positioned within a housing of the downhole choke.This throttle design has the following disadvantages:
- limited capacity gas from the upper layers, because of its structural features do not allow to increase the entrance inner diameter of 8-10 mm in the most common construction of wells with diameter of the production casing to 168 mm and diameter of tubing equal to 89 mm (see table).- throttle design does not exclude the possibility of uncontrolled flow of gas or other fluid in the tubing from the top nadakarni seams and works to stimulate the flow of gas, research, isolation and repair work on the lower podplacenym layers. In these cases, the choke should be removed and instead be installed in the side pocket mandrel blank tube.When creating a device was solved the following tasks:
- increase propuschennyj tubes;
- exclude the flow of gas to the lower podvecerni at the top nadakarni layers when you stop the well without killing;
- exclude the flow of gas in the tubing when the renovations in the well when the pressure in this space against the throttle is greater than the pressure in the tubing.These technical problems are solved due to the fact that in the downhole choke, comprising a housing with apertures, a spring-loaded check valve and a replaceable nozzle, the housing top and bottom are made connecting thread, with which it is attached directly to the tubing, the casing is provided with a casing, and a check valve and a replaceable nozzle located in the annular gap between the housing and the cover, while inside the body is placed a sleeve with holes, with the possibility of shifting tool cable techniques for combining or uncoupling of the holes of the sleeve and the hole of the housing.The drawing shows a diagram of the downhole choke (longitudinal section along the line a-a).The downhole choke consists of a housing 1 with 2 holes, top and bottom which is made from thread 3 and 4. The housing 1 is equipped with Kozue spring 10. Inside the housing 1 is placed a sleeve 11 with holes 12.The downhole choke works as follows.Before descending into the well downhole choke attached to the upper pipe lower section of tubing to the bottom of the upper pipe section of tubing with mounting threads 3 and 4. After the descent of the downhole choke on tubing and installation of the packer, instrument cable technology shift the sleeve 11 up to align the holes 12 with the holes 2 of the housing 1. Backwashing open the check valve 7 and learn the well to the flow of clean gas. After completion of the force of the spring 10 is closed check valve 7, and then the well is put into operation. During operation of the well in the lower layer of the pressure in the tubing against the downhole choke becomes smaller than the pressure of the upper nadakarni layer. Under the influence of a pressure differential check valve 7 is shifted upwards, overcoming the force of the spring 10, thus ensuring the access of gas from the upper nadakarni reservoir into the tubing through the removable nozzle 8 and the annular gap 6 between the cover 5 and the housing 1 and is ADCI 8. After stopping the well pressure inside the tubing and downhole choke lines. At this point, the spring 10 returns the check valve 7 in the saddle 9. This eliminates the flow of gas from the lower reservoir at the top, when the pressure in the tubing is greater than the pressure of the downhole choke (during idle wells under the gas). If you want to completely eliminate the flow of gas or other fluid in the tubing from the upper reservoir when the workover of the sleeve 11 to move the instrument cable technology for the separation hole 12 and hole 2 of the housing 1, allowing the entrance of gas into the tubing.The proposed design of the downhole choke makes it possible to increase the throughput of gas, since the flow area compared to the prototype to 20-30 times (see table) and, thereby, to extend the range of operating flow rates of gas from the top of the object, to provide favorable conditions for development wells without the use of standard circulation valve.When carrying out works to stimulate the flow of gas and other works in the upper nadakarni reservoirs wells, installation of the proposed inductor directly the bottom podvecerni at the top nadakarni layers, that eliminates the need for installation in the side pocket mandrel hollow tube.The application of the proposed bottomhole choke sleeves with holes provides a complete seal between the pipe space and tubing during repair works in the well.Sources of information
1. Directory OKB Neftemash "Equipment for the exploitation of oil and gas wells with devices to prevent outdoor fountains". M, CONTAINERTYPES, 1989, S. 90.2. Camco Gas Lift Product Catalog Retrievable Single - Point - Injection Gas Lift Orifice Valves, 1993, c. 22. In translation: the Catalogue of the firm Camco, 1993, S. 22.Retrieved diaphragm valve single acting (for a permanent, one-way gas flow in the tubing from the annulus). Type of CSD-2, ASD-3. The downhole choke placed on the tubing and comprising a housing with apertures, a spring-loaded check valve and a replaceable nozzle, characterized in that the housing top and bottom are made connecting thread, with which it is attached directly to the tubing, the casing is provided with a casing, and a check valve and a replaceable nozzle located in the ring the yoke instrument cable technology for combination or separation of the holes of the sleeve and the hole of the housing.
FIELD: oil and gas extractive industry.
SUBSTANCE: valve has body of steel, throttling assembly, locking assembly with ball and saddle for it. Between locking and throttling assemblies resilient impenetrable wall separating these is mounted fixedly with possible interconnection via U-shaped, turned by its knee upwards, tubular channel, with inner diameter greater than ball diameter, having two branches directed downwards and having various lengths. Elongated pipe branch is connected through open end fixedly placed on wall to hollow of body throttling assembly. Short branch end is placed above wall and is within hollow of locking assembly. Short branch pipe is extended above the knee for distance greater than ball diameter. It is made in form of branch pipe with closed upper end, forming a hollow - tank with stopping device for placement and holding of ball therein in starting position. Ball can possibly fall freely under its own wait in downward direction onto saddle if released by stop as a result of effect from outside force from cementing plug at the end of cementation.
EFFECT: higher reliability, better quality.
7 cl, 8 dwg