RU2275503C2 - Wellhead sampler for production well - Google Patents

Abstract

FIELD: oil production industry, particularly equipment to take gas-and-liquid mixture samples at well head.

SUBSTANCE: sampler comprises tubular body mounted in pressure pipeline at well head, sample taking chamber and shutoff member. The tubular body is thick-walled and has end parts made as truncated cones with lesser bases facing each other and communicated by channel having diameter equal to lesser base diameter. Larger cone bases have equal inner diameters and equal to pressure pipeline diameter. Coaxial side channels are created within the bounds of through channel of tubular body. Pipe for reagent, namely demulsifier supplying in well product, is installed in one side channel. Air-tight seat of shutoff member is installed in another channel having several steps so that the seat is located in larger step thereof. The shutoff member has corresponding conical surface for air-tight seat creation and is installed in sample taking chamber having discharge pipe. End part of shutoff member is connected with tubular body by threaded connection and is terminated in extension for socket key and groove for screwdriver receiving. To provide uniform state of well product inner conical body walls are provided with rigidly fixed blades, namely turbulators, secured in flow direction. Discharge pipe and sample taking chamber have caps to prevent unauthorized oil sampling or discharge thereof at well head.

EFFECT: increased reliability of information concerning formation products due to increased sample quality and extended functional capabilities due to possibility to combine device for chemical demulsifier reagent introduction in oil to be conveyed, prevention of unauthorized formation product production or discharge thereof at well head.

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Description

The invention relates to the field of oil industry, namely, oilfield equipment for sampling a gas-liquid mixture at the mouth of an oil well for analysis.

A device for sampling at the mouth of a producing well [1] is known, comprising a housing with inlet and outlet nozzles, a ground stopper with two holes A and B and a handle for its rotation through 90 °. It also contains breathing and drain pipes. To seal the plug in the housing, it is equipped with an stuffing box and a union nut.

There is also known a device for sampling at the mouth of a producing well [2], comprising a hollow body mounted in a pressure pipe of a wellhead reinforcement, inside of which a gas-liquid mixture flow control element with sealing elements and a control handle, a selective chamber, a shut-off element and guide tube.

This device is in technical essence closer to the proposed one and can be adopted as a prototype.

A common drawback of both analog and prototype is the complexity of the design, as well as the selection of low-quality samples. This is explained by the fact that the gas-liquid mixture is stratified in the pressure pipe, while water predominantly occupies the lower part of the pipeline, thereby distorting the information received on the sample taken. In addition, the presence of a handle or valve for controlling the shut-off element brought out allows unauthorized selection of formation products or merging it into the near-wellbore zone, creating an explosive and fire hazard situation.

The objective of the present invention is to remedy the above disadvantages.

The task is achieved in that in the wellhead sampler for the producing well, comprising a tubular body mounted in a pressure pipe at the wellhead, a sampling chamber and a shut-off element, the tubular body is thick-walled, its end parts are made in the form of a truncated cone, the smaller bases of which are directed to each other and communicated with each other through a passage with a diameter equal to the diameter of the smaller bases, large bases of the cones are equal to each other in internal diameter and equal to the diameter side of the pressure pipe pipeline, within the passage channel of the tubular body, side channels are made along one axial line, in one of which a tube for supplying the reagent - demulsifier to the well production is installed, and in the other, which is performed in steps, a sealed shut-off element saddle is installed in a larger step, the last made with a mating conical surface under a tight seat and installed in a sampling chamber with a drain pipe, the tail of the locking element is connected to the tubular body by a threaded connection It ended with a protrusion under the socket wrench and a groove for the screwdriver, moreover, to bring the well production stream into a uniform state, the conical inner walls of the body from the flow inlet side are equipped with rigidly fixed blades - turbulators, and from unauthorized oil extraction or drainage at the wellhead and the sampling chamber is provided with covers.

The invention is illustrated in the drawing, where Fig.1 shows a General view of the wellhead sampler mounted on the pressure pipe, Fig.2 is a view A in Fig.1, where the sampler is shown in the operating position, in partial section, and Fig.3 - view in figure 2, where the blades are visible for turbulence of the incoming stream into the sampler body.

The wellhead sampler comprises a thick-walled tubular body 1, the end parts of which are made in the form of a truncated cone (see FIG. 2), the smaller bases 2 and 3 of which are directed towards each other and communicated with each other through a passage 4 with a diameter equal to the diameter of the smaller bases. The large bases of the cones are equal in internal diameter and equal to the diameter of the pressure pipe 5, which are mounted by welding. Within the passage channel 4 of the casing, side channels 6 and 7 are made along one axial line, in one of which, for example, in channel 6, a tube 8 is installed for supplying the reagent - demulsifier to the production of the well, and in the other, performed stepwise, at a higher stage of which a saddle 9 of the locking element 10 is installed, the latter is made with a tapered surface under the saddle and is placed in the sampling chamber 11 with a drain pipe 12 that is closed after sampling by the cover 13. The tail portion 14 of the locking element is connected to the housing by a threaded connection and is made with a protrusion 15 for a socket wrench and a groove 16 for a screwdriver for opening and closing the passage channel of the seat 9 with a locking element. The camera 11 after completion of the sampling is closed by a cover 17.

In order to bring the well production flow within the cone 18 and channel 4 to a uniform state, its internal walls are provided with rigidly fixed blades 19 for turbulence of the flow from the flow inlet side.

Wellhead sampler works as follows. It is assembled, as shown in figure 2, permanently mounted on the flow line of the wellhead reinforcement 20 of the well, i.e., on the pressure pipe 5 by welding (see figure 1) in the idle position. At the same time, the incoming gas-oil mixture from the well with the open valve 21 through the pressure pipe 5, getting on the blades 19 of the cone 18 of the body, is twisted, getting a turbulent movement. The flow cross section inside the truncated cone decreases as it moves, enhancing the mixing effect, thereby bringing the flow to a homogeneous state. Then a homogeneous liquid enters the channel 4, where the flow acquires a minimum cross-section, which is an obstacle to its re-separation into phases, and a condition that ensures the preservation of the acquired uniformity within this channel.

If it is necessary to take a sample for analysis, first unscrew the caps 13 and 17 from the drain tube and the chamber 11 for sampling. Then, the locking element 10 is unscrewed with a socket wrench or a screwdriver, thereby opening the passage channel of the seat 9 for the sample to be taken into the chamber 11, from where it enters the receiving tank 9 through the drain pipe 12 (the receiving tank is not shown in the drawing). At the end of the sampling of the required volume with a socket wrench or a screwdriver, the locking element 10 is moved in the forward direction until it is seated on the saddle 9. Then, the drain pipe and the sampling chamber 11 are closed with covers 13 and 17, respectively. If necessary, the sampling is repeated. Thus, the placement of the locking element 10 in the sampling chamber, which is closed by a lid, makes it unavailable to take unauthorized wells or drain them into the mouth, thereby preventing a fire or explosion hazard.

Having opened the shut-off element 22 on the reagent supply pipe, reagent-demulsifier is constantly fed into the stream through the pipe 8.

The technical and economic advantage of the proposal is as follows.

The use of the inventive wellhead sampler provides reliable information about the production of the reservoir by improving the quality of the sample taken, and this will improve the accuracy of the determined technological parameters, which ultimately will allow the optimal development of oil reservoirs. The sampler has enhanced functionality by combining a device for introducing a chemical reagent - demulsifier into the transported oil.

It is compact, makes a closed system in an idle position, which prevents unauthorized selection of formation products or its discharge at the wellhead.

Information sources

1. SU No. 220194 A1, cl. E 21 B 49/02, G 01 N 1/10, 01/01/1968

2. RU No. 2151290, cl. G 01 N 1/10, 06/20/2000 (prototype).

Claims (1)

Wellhead sampler for an producing well, comprising a tubular body mounted in a pressure pipe at the wellhead, a sampling chamber and a shut-off element, characterized in that the tubular body is thick-walled, its end parts are made in the form of a truncated cone, the smaller bases of which are directed towards each other and communicated with each other through a passage with a diameter equal to the diameter of the smaller bases, the large bases of the cones are equal to each other in internal diameter and equal to the diameter of the pressure pipe water, within the passage channel of the tubular body, side channels are made along one axial line, in one of which there is a tube for supplying a reagent - demulsifier to the production of the well, and in the other, which is performed in steps, a sealed shut-off element saddle is installed in a larger step, the latter made with mating conical surface under a sealed seat and installed in the sampling chamber with a drain pipe, the tail of the locking element is connected to the tubular body by a threaded connection and the end is a socket for a socket wrench and a groove for a screwdriver, moreover, to bring the well production stream into a uniform state, the conical inner walls of the body from the flow inlet side are equipped with rigidly fixed turbulator blades, and from unauthorized oil extraction or drainage at the wellhead, a drain pipe and a chamber for sampling equipped with caps.

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