RU2081311C1 - Method and device for gas condensate investigation of wells - Google Patents

Abstract

FIELD: gas and oil industry. SUBSTANCE: method relates to well development of gas and gas condensate fields and regulation of operating modes of production wells. At each steady state mode, well product is directed to set of separation units through swirling member. Swirled flow of well product is directed to separation unit where due to incline angle of slots in perforated pipe union additional swirling of flow takes place. After discharge from slots at tail part, flow enters expansion chamber where swirling is continued. Liquid and hard phases are withdrawn into containers for collection. Dry gas is directed to gas flow rate meters, through individual pipeline it goes to general gas field product collector. Prior to stabilization of all hydrodynamic parameters, performed are regular measurements of pressure and temperature. Degree of filling containers is determined by pressure gauge, liquid and hard phases are regular bypassed by means of gate valves to measuring tanks 9 during entire steady state mode of operation. Operating period is checked by stopwatch. When steady state mode of operation comes, recorded are values of steady state pressure, temperature, gas flow rate and amounts of gas condensate, water and mechanical impurities during period of operation in this mode. Then dry gas sample is taken. Certain amount of gas condensate in steam phase created in measuring tank is withdrawn through safety branch line from site of investigation and utilized. EFFECT: high efficiency. 3 cl, 4 dwg

Description

 The invention relates to the field of downhole development of gas and gas condensate fields, in particular to gas condensate research, the regulation of technological modes of production wells.

 A known method of gas-dynamic studies of gas and gas condensate production wells at stationary filtration and flow regimes in the well, which consists in measuring the formation and bottom-hole pressures and temperatures at each mode, the flow rate of the well with subsequent determination by calculating the productive characteristics of the discovered formation.

 There is a method of gas-dynamic studies without the release of gas into the atmosphere, where it is envisaged to conduct such studies of an individual well with the separation of multiphase production, by measuring the gas flow rate during the development of the well through a separator, at a gas collection point (GSP), UKPG. Here, samples taken out by the gas stream and separated phases are also taken for subsequent laboratory analysis.

 The disadvantage of this method and device is that it does not provide the required quality of well research, complete characterization, since the phases that spontaneously precipitated and accumulated in the well plume influence the accuracy of measuring gas flow at SHGs and gas treatment plants. The hydraulic and thermogasdynamic characteristics of the plume, soil, ambient air, etc. also affect.

 Thus, the removal of full indicator curves, metrological accuracy of measuring gas flow rate is not achieved.

 A known method of gas-hydrodynamic research of gas and gas condensate wells, where the separation of products, measuring the flow rate of gas and the carried out liquid and solid phases and sampling is carried out at the wellhead.

 At the same time, the research device is aimed at reducing metal consumption, facilitating installation and transportation. However, this method and device do not allow high-quality gas condensate studies, since they do not have devices and devices specifically for separating the gas condensate phase, which requires large volumes of separation, low hydraulic resistance of the separation device. These shortcomings do not allow to completely separate the precipitated liquid from gas, to measure the total amount of separated gas condensate in one (each) stationary mode, and thereby reduce the information content of the study and metrological accuracy of measurements.

 A device is also known, including separation blocks, a gas flow meter, liquid and mechanical impurities collectors, in one of the separation blocks the pipe is mounted for rotation around its longitudinal axis and is made in the form of a perforated truncated cone.

 The disadvantage of this device is that the blade swirling element creates additional hydraulic resistance in the device, which does not allow to correctly evaluate the production capabilities of the investigated well at high (due to the blade swirling element) pressure at the wellhead. The plates provided in the device, the perforated protective casing also increase the hydraulic resistance of the device, while gas condensate studies require an increase in the flow cross section and its multiple expansion and contraction.

 The purpose of the invention is improving the quality of research and measurement accuracy, increasing the degree of separation of gas condensate, produced water and solids while reducing the hydraulic resistance of the installation as a whole.

 This goal is achieved by the fact that the proposed method of gas condensate research of wells conducted at the wellhead, including the separation of the production of the well, measuring the flow rate of gas and outflow phases, sampling the phases and analyzing them, measuring wellhead and bottomhole pressures and temperatures during well operation in several established modes, in this case, the separation of products is carried out with the number of separation blocks corresponding to the potential content of condensate in the gas, the collected liquid and solid phases are accumulated and passed into a measuring device for each the house is stationary and take measurements.

The proposed method is carried out using a device for gas condensate well research, including separation blocks, a gas flow meter, a device for measuring pressure and temperature, a nozzle with holes mounted for rotation around a longitudinal axis, a screw element at the entrance, while the screw element is made in the form "snails" with a tangential input of well products, separation blocks are detachable, each with a rotating cylindrical pipe with profiled holes tures, providing an increase in rotation speed of the nozzle, the latter separation unit is designed as a perforated nozzle with a stationary cylindrical filter surface, all provided with fairings separation tubes from the incoming product stream and the end sections are in the form of hemispherical cavities are formed when connecting the expansion chamber. The profiled openings according to claim 2 are made in the form of slotted slots at an angle of 45 ^o to the axis of rotation, and in the head of the pipe to the first support of rotation, the slots are directed against the product flow, and in the rest, in the direction of the flow in circular rows or staggered.

 A comparison of the claimed technical solutions with the prototype made it possible to establish their compliance with the criterion of "novelty." Since the study of other well-known technical solutions in the field of technology features that distinguish the claimed technical solution from the prototype were not identified, they provide the claimed technical solution according to the criterion of "significant differences".

 In FIG. 1 presents a schematic diagram of the strapping of a device for conducting gas condensate research by the present method; in FIG. 2 is a general view of a device for gas condensate well surveys; in FIG. 3 - section aa; in FIG. 4 section BB.

 The schematic diagram of the strapping of the device for gas condensate research includes a set of separation blocks 1, high pressure containers 2 for preliminary collection of the separated liquid and mechanical impurities, the outlet pipe of the separation pipe of the last section 3, a flow meter for dry gas 4, fittings for connecting pressure gauges 5, a thermowell 6, fitting for gas sampling 7, valves 8, measuring device 9, bypass safety line 10, control valve 11.

 A device for gas condensate research (Fig. 2) includes a twisting element 1, a separation unit 2 with a cylindrical pipe 3, in which profiled holes 4, rolling bearings 5, hemispherical cavities 6, 7, which, when connected, form an expansion chamber, a fairing 8, taps for connecting containers 7.

 The last section contains a stationary pipe 10 with a perforation 11, a cylindrical filter 12, a fairing 13, an outlet for connecting containers 14, a cover 15, a gas flow meter 16, fittings for connecting a manometer 17, a thermowell 18, a fitting for sampling gas 19, flanges 20.

 In FIG. 3 shows a cross section AA of a general form, including a tangential nozzle 1 and a swirl zone 2.

 In FIG. 4 shows a section BB, where the section of the housing of the separation unit 1, the section of the cylindrical pipe 2.

The essence of the method lies in the fact that at each stationary mode, the production of the well is sent to a set of separation blocks 1 (Fig. 1) through a twisting element 1 (Fig. 2). A rotating product stream, passing through the separation blocks 1 (Fig. 1), rotating nozzles 3 (Fig. 2) and expansion chambers, is divided into phases. In this case, the product flow swirling using element 1 (Fig. 2) enters the separation unit 2 (Fig. 2), bypassing the fairing 9 (Fig. 2) of the separation pipe 3 (Fig. 2), and then through the slotted slots 4 (Fig. 2) in the head of the pipe 3 (Fig. 2) gets inside it. The direction of the slots 4 (Fig. 2) and the angle of inclination of these slots at 45 ^o provide a twist perforated pipe 3 (Fig. 2). After passing through the pipe 3 (Fig. 2), the product flows into the separation unit 2 (Fig. 2) through the slotted slots 4 (Fig. 2) in the middle of the pipe 3 (Fig. 2) between the rolling bearings 5 (Fig. 2). The direction of the slots 4 (Fig. 2) and the angle of inclination in this part of the nozzle provide a further twist of the nozzle 3 (Fig. 2) when the product flows out through the slots 4 (Fig. 2). Similarly, flowing out from the slotted slots 4 (Fig. 2) in the tail section, the product flow continues to twist the entire pipe 3. The rotation of the pipe 3 and the slotted holes 4 provide a high degree of phase separation. The liquid and solid phases are collected in containers 2 (FIG. 1), where they accumulate. The "dry" gas is directed to a gas flow meter 4 (Fig. 1) and then to the general field production collection system through an individual well loop. Before stabilization of all gas-hydrodynamic parameters, systematic pressure measurements are made using the nozzle 5 (Fig. 1) and the gas flow temperature using a thermowell 6 (Fig. 1). Determining the degree of filling of containers 2 (Fig. 1) using pressure gauges, the liquid and solid phases are systematically transferred with the help of valves 8 (Fig. 1) to the measuring device 9 (Fig. 1) during this entire stationary mode, the time of which is measured by a stopwatch. After the onset of the stationary mode, the values of stationary pressures, temperature, gas flow rate and the amount of gas condensate, water and mechanical impurities during the operation of the mode are recorded. After that, through the nozzle 7 (Fig. 1), a sample of “dry” gas (in triplicate) is taken into a special portable high-pressure container with fixed gas-dynamic parameters for high-quality laboratory analysis and calculations.

 The control valve 11 (Fig. 1) will not allow the liquid to spontaneously spill out of the containers 2 (Fig. 1) into the measuring device 9 (Fig. 1), and along the outlet safety line 10 (Fig. 1) a certain amount of gas condensate in the vapor phase formed in measuring device 9 (Fig. 1), divert from the study site, collect and dispose.

 Then go to the next stationary mode and repeat the operation.

 The number of separation blocks 2 (Fig. 2) in the set is selected depending on the expected specific potential content of gas condensate in the produced gas: the higher the potential content, the more separation blocks, perforated nozzles, expansion chambers and high-pressure containers.

 The measured gas-hydrodynamic parameters of the well and the parameters of the "dry" gas, gas condensate, other collected liquids and mechanical impurities are subjected to theoretical processing in order to obtain reliable information about the productive formation opened by the well and its saturating fluids, including reserves and condensate production. Based on the research results, the number of separation blocks in the set for the study of similar wells is adjusted.

 Thus, the described device and its operation provide gas condensate studies of the wells in the described manner with the most complete separation of gas condensate from the “dry” gas, other liquids and mechanical impurities, the most metrologically accurate measurement of the flow of “dry” gas (well flow rate) and thereby increase research quality; this allows us to conclude that the claimed technical solutions are united by a single inventive concept.

Claims (3)

 1. The method of gas condensate research conducted at the wellhead, including the separation of products, measuring the flow rate of gas and the phases to be removed, sampling the phases and analyzing them, measuring wellhead and bottomhole pressures and temperatures during well operation in several established modes, characterized in that the separation of products carried out at the number of separation blocks, determined experimentally for each reservoir or production facility in accordance with the established in the process of preliminary gas condensate studies well of the specific potential gas condensate content in the produced gas, the collected liquid and solid phases are accumulated and transferred to the meter in each stationary mode and the actual potential gas condensate content is measured.  2. A device for gas condensate well research, including sequentially connected separation blocks, a gas flow meter, pressure and temperature measuring devices located at the inlet and outlet, a perforated nozzle mounted for rotation around the longitudinal axis, and a screw element at the entrance, characterized in that the twisting element is made in the form of a snail with a tangential input of the well products, the separation blocks are detachable, each with a rotating cylindrical perforated nozzle with profiled holes, the last separation unit is made in the form of a stationary perforated nozzle, which is equipped with a cylindrical surface filter, while all nozzles are equipped with fairings on the side of the incoming flow of products, and the inputs and outputs of the separation blocks, except the output of the last separation unit, are made in the form hemispherical cavities forming expansion chambers with serial connection of separation blocks. 3. The device according to p. 2, characterized in that the profiled holes are made in the form of slotted slots at an angle of 45 ^o to the axis of rotation, and in the head of the perforated nozzles, except the last, up to the first support of rotation, the slots are directed against the flow of products, and the rest pieces in the direction of flow in circular rows or staggered.

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