SU881309A1 - Down-hole flush-through core sampler - Google Patents

Description

(54) DEPTH FLOW TEST PROCESSOR

one

The invention relates to the oil industry, and more specifically to the study of wells.

A known sampler containing a receiving chamber in the form of a cylinder, in the lower part of which a receiving valve is installed. A piston moves in the cylinder. During the descent into the well, the piston rod is held in the lower position with the help of a lock and a tape fixed at one end to the lock, and the other end to the squib. To take a sample, the piston is moved to the lower position, close the lock and lower the sampler to a predetermined depth. After a predetermined time has elapsed, the clock mechanism closes the contacts and an explosion of the squib occurs, which releases the lock. In this case, the sampler raises the rc up Ij.

The PD-3 sampler is known, containing a receiving chamber, a clock mechanism, upper and lower valves, and a valve closing mechanism. The sampler is lowered to a predetermined depth. The cavity of the sampler from the valve to the valve (receiving chamber) is filled with oil. Continuously working clock mechanism, rotating the friction system, transmits the rotation to the shaft

with the screw, sliding the nut from the screw while pressing the pin on the valve closing mechanism ring. At the same time, the upper and lower valves are pressed against their seats and the oil sample is cut off at the sampler.

However, the designs of the above described samplers do not allow the sampling of high-quality samples in wells with bottomhole pressure below the saturation pressure, due to the unlimited position of the samplers in the production string. Thus, despite the fact that this

15 The sampler is designed for sampling a two-phase mixture; it does not provide an objective determination of the parameters of the sample being taken.

20

Also known is a deep flow sampler PD-4, comprising a housing with a sampling chamber, an upper and lower valve interconnected by a tight mechanism through a lock mechanism, and a valve control mechanism. The PD-4 sampler is designed to take a sample in case the moving oil flow is two-phase. For this purpose, its valve mechanism is designed in such a way that the lower valve

the pan closes slightly before the top. At the moment when both valves are open, a two-phase flow passes through the sampler. After the bottom valve closes, the free gas entering the sampler must exit through the open top valve, due to the difference in specific gravities of gas and oil, and be replaced with additional oil through the top valve. After some time, the upper valve is closed, after which the sampler is removed from the well,

This sampler does not allow high-quality sampling in wells with bottomhole pressures below saturation pressure, i.e. when a two-phase gas-oil mixture arrives at the bottom, which reduces the representativeness of the sample. This is explained as follows. When dvizhenii in the lift pipes of a single-phase mixture, the distribution over the cross section of the flow of passing gas bubbles, according to the laws of hydraulics, is uneven. In the middle part of the pipe, the concentration of gas becomes maximum, and along the edges of the pipe, the minimum, and since the sampler in the well can occupy a position both in the center of the stream and at. the sample walls, the biphasic mixture entering the sampler is either enriched or depleted in gas. Therefore, the gas factor of a two-phase sample taken in a well is always different from the gas factor of the two-phase mixture entering the bottom.

The purpose of the invention is to increase the reliability of the sample by taking a sample in the squashins with a bottomhole pressure below the saturation pressure.

This goal is achieved by the fact that the sampler is equipped with a nozzle with radial windows, with a packer assembly in the lower part and placed inside it with a cutter made in the form of a cylindrical cup, in the upper part of which through holes are made, and the nozzle is rigidly connected to the lower part of the body, and The picker is mounted so as to overlap the radial windows of the nozzle and is rigidly connected to the thrust.

The presence in the sampler of a packer assembly allows the entire gas-liquid mixture of the well to be directed into the cavity of the extraction chamber. The presence of the body compartment allows the flow direction of the well to be changed.

The drawing shows a diagram of the depth sampler, a general view.

The sampler includes a housing 1 with a sampling chamber 2, overlapped with the upper 3 and lower 4 valves, which connect: each other with a tight 5 through a locking mechanism 6. T he 5 interacts with the mechanism

control valves 7, is rigidly connected to the shut-off device 8, which has sloping bore holes 9. The cut-off device 8 is located in the nozzle 10, in the upper part of which there are radial windows 11, and the lower part is equipped with a well-known packer unit 12, for example of an umbrella type. In the upper part of the sampler there are radial windows 13.

The sampler works as follows.

The sampler is lowered to a predetermined depth with the valves open and are packaged with unit 12. In this case, the cutter-8 is positioned so as to cover the radial windows 11, the branch pipe 10.

The entire well-fluid mixture of the well passes through the packer unit 12 through the through holes of the cutter 8 into the sampling chamber 2 and exits through the radial windows 13. At the same time, high-quality sampling is ensured.

When the control mechanism of valves 7 of valve 3 and 4 is triggered, a sample is cut off in chamber 2. Simultaneously connected to the thrust 5, the cutter 8 is lowered down, opening access of the well fluid through the through-holes 9 of the sampler.

This depth sampler provides, in comparison with the known technical solutions, the possibility of objectively determining the parameters of oil by taking high-quality samples in wells with bottomhole pressures below the saturation pressure. In the oil and gas industry, the use of the invention allows to obtain complete and reliable data characterizing the properties of reservoir oil when calculating oil reserves, designing the development and operation of oil deposits, as well as choosing the optimal operating conditions to expand the range of wells that can be covered by the study.

Claims (3)

1. Authors certificate of the USSR 114255, cl. E 21 49/02, 1956. 2.Mamuna V.M. and others. Depth samplers and their application. M., Gostoptehizdat, 1961, p. 37. 3.Mamuna V.M. and others. Depth samplers and their application. M., Gostoptehizdat, 1961, p. 57 (prototype).