RU2179240C1 - Method and device for determination of gas factor at wellhead of well in operation - Google Patents

Abstract

FIELD: oil- and gas-producing industry. SUBSTANCE: device for method realization consists of body with inlet and outlet pipes of main flow and valve. Body accommodates sampling tube whose wall has radial channel in which membrane is located. Flows inside tube and inside body interact due to membrane deformation to equalize static pressures of flows. Invention is used for taking samples of gas-liquid flow for determination of gas factor of gas-oil wells. Invention allows increasing accuracy and simplification of creation process and control of isokinetic conditions of flows current irrespective of flow rate due to automatic balancing of static pressures of sampled and main flows to ensure isokinetic conditions of current of sampled flow. EFFECT: higher accuracy of determination of gas factor and simplified process of determination. 2 cl, 2 dwg

Description

 The invention relates to the oil and gas industry and can be used to determine the gas factor at the mouth of an existing well.

 A known method for determining the gas factor by taking part of the gas-liquid stream, including creating a homogeneous medium by intensively mixing the main stream and sampling under the isokinetic mode of flow of the main and selected flows. A device for implementing this method comprises a housing with an isokinetic probe placed therein and a flow turbulator in the form of a nozzle with a turbulent grating coaxially mounted in the housing [1].

 The disadvantages of this method and device are the lack of homogenization of the gas-liquid medium and the difficulty in ensuring the isokinetic mode of flow, since it must be constantly monitored and maintained.

 A known method and device for determining the gas factor, taken as a prototype, including sampling a gas-liquid stream by creating a homogeneous environment in the sampling zone and the isokinetic flow regime of the main and sample flows, while creating a critical zone of the main gas-liquid stream and sampling from this zone with a critical flow rate of the selected stream, while critical flow regimes of the main and selected flows are created by installing fittings in the flow path. A device for implementing this method comprises a hollow body with channels for inlet and outlet of the flow and a sampling tube located in the cavity of the housing, while in the housing and at the entrance to the sampling tube interchangeable fittings are installed with passage sections providing the establishment of critical flow regimes of gas-liquid flows, and the sampling the tube is placed so that the entrance to it is in the critical expiration zone of the main gas-liquid flow. The device is also equipped with check valves installed in the housing in front of the fitting in the sampling tube [2].

 The advantage of this method and device for its implementation in comparison with the analogue is the better homogenization of the gas-liquid medium of the gas-liquid flow by using interchangeable fittings and the best providing isokinetic flow patterns.

 The disadvantage of the prototype is the complexity and low accuracy of creating an isokinetic flow due to the pulsating flow rate (well flow rate), which complicates the selection of the nozzle orifice, and the need to create a critical zone of the main gas-liquid flow, which is achieved by changing the diameter of the nozzle, is negative. the turn leads to a change in the initial operating mode of the well during the measurement, while the values obtained as a result of such a measurement will characterize and The changed mode of operation of the well, not the original one.

 The objective of the invention is to improve the accuracy and simplification of the process of creating and regulating the isokinetic regime of the flow of flows regardless of the flow rate (flow rate of the well), namely the degree of pulsation of flows in the well, and the creation of a device that allows measurements of the gas factor and flow rate at the initial operating conditions of the well.

 The problem is solved in that when determining the gas factor at the wellhead of an operating well, including the creation of an isokinetic mode of flow of the sampled and main streams, the isokinetic mode in the sampled stream is automatically controlled by balancing the static pressures of the sampled and main streams.

 The essence of the invention lies in the fact that in the device for determining the gas factor at the mouth of an existing well, comprising a hollow body with holes for the inlet and outlet of the main stream and a sampling tube located in the body cavity, a radial channel is made in the wall of the tube in which the membrane is located.

 The invention is illustrated by diagrams, where in FIG. 1 is a vertical sectional view of a device for implementing the method; in FIG. 2 is a diagram of the operation of the device on an existing well.

 The proposed method is based on the hydrodynamic interaction of the selected and main flows.

 The method is implemented by a device that ensures the passage of part of the stream through the sampling tube, and the main stream through the cavity of the housing parallel to the tube.

 The device (Fig. 1) for determining the gas factor consists of a hollow body 1 with holes for input 2 and output 3 of the main stream, a sampling tube 4 with a channel 5 with a membrane 6 located in it, the body 1 is equipped with a valve 7.

 In FIG. 2 presents the valve 8 and the fitting 9 downhole strapping.

The method is implemented as follows:
When the gate valves 8 and valve 7 are opened (see Fig. 2), mixing on the borehole fitting 9, the main part of the well production flow passes through the cavity of the housing 1, while through the tube 4 a part of the flow enters the separator (not shown in the diagram), when this, the flows inside the tube 4 and inside the housing 1 interact due to the deformation of the membrane 6, as a result of which the static pressure of the flows is automatically equalized, which leads to an isokinetic sampling mode throughout the entire measurement.

 The method and device for determining the gas factor at the mouths of existing wells was tested at the Yuzhno-Yagunskoye field of the Kogalymneftegaz TPP and at the Severo-Gubkinskoye field of the joint venture Geoilbent LTD.

Sources of information
1. ASCSR N 1810522, Mcl. E 21 B 47/10, 1990.

 2. RF patent N 2091579, Mcl. E 21 B 47/10, G 01 N 1/10 (prototype).

Claims (2)

 1. The method of determining the gas factor at the mouth of an existing well, comprising creating an isokinetic mode of flow of the sampled and main streams, characterized in that the isokinetic mode is automatically controlled in the sampled stream by balancing the static pressures of the sampled and main streams.  2. A device for determining the gas factor at the mouth of an existing well, comprising a hollow body with nozzles for entering and leaving the main stream and a sampling tube located in the body cavity, characterized in that a radial channel is made in the tube wall in which the membrane is located.

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