RU2632691C1 - Method for determining the separation coefficient - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method for determining the separation coefficient involves feeding the fluid contaminant into two separators, installed in series along its movement. In this case, the fluid is fed to the separators within a predetermined time interval necessary to accumulate a sufficient amount of contaminant trapped by the separators, after which the amount of the contaminant is measured in the first and second fluid flow separators. Thereafter, a fluid is supplied with the same flow rate and contaminant content, bypassing the first separator to the second one, within another predetermined time interval necessary to accumulate a sufficient amount of trapped contaminant to measure, after which this contaminant amount is measured and the separation coefficients of the first and second separators according to the formulas:

EFFECT: increasing the accuracy of separation coefficients determination.

1 ex

Description

The invention relates to the field of the oil and gas industry and can be used to determine the separation coefficients of fluid treatment plants, as well as separators, designed to control the content of impurities in the fluid stream.

A known method for determining the separation coefficient, including measuring the amount of impurity trapped by the separator, and the amount of impurity in the ablation meter after the separator at a steady state flow of fluid through the separator [Methodological guidelines for a comprehensive study of technological installations for preparing gas and condensate for transport. - M.: VNIIEgazprom, 1979, p. 28-29].

The disadvantage of this method is the need to install after the separator a special ablation meter that selects only part of the gas flow, which can lead to significant measurement errors in case of uneven distribution of fluid over the pipe cross section. In addition, in the strapping of the separator, a special device must be installed for introducing measuring probes into the gas sampling pipe, which is often absent.

A known method for determining the separation coefficient using two separators installed sequentially along the gas, including measuring the amount of impurities trapped in the separators [Patent for invention No. 2169604 "Method for determining the separation coefficient" from 06/27/2001]. For various characteristics of the separators, it is additionally required to install them in the reverse order, after which the impurity fluid is again fed into the separators and the amount of impurities trapped in them is measured. Only after this is it possible to determine the separation coefficients of each separator.

The disadvantage of this method is the impossibility of its use for separators, which cannot be installed first in direct and then in reverse order, for example, for stationary separators. In addition, with a high separation coefficient, very small volumes of liquid will be captured in the second downstream gas separator, which will lead to a decrease in measurement accuracy.

The objective of the invention is to develop a method for determining the separation coefficient without the use of special measuring equipment that does not require additional reinstallation of the separators and improves the accuracy of measurements.

The technical result is achieved by first connecting two separators, through which the impurity fluid passes sequentially, and then one separator.

The aim of the invention is to improve the accuracy of the results and reduce the cost of determining the separation coefficient.

This goal is achieved by the fact that in the proposed method for determining the separation coefficient, which includes supplying impurity fluid to two separators installed sequentially in the direction of its movement, the fluid is fed into the separators for a predetermined period of time necessary to accumulate the amount of impurity captured by the separators after the completion of which the amount of impurity is measured in the first and second separators in the direction of the fluid, and then the fluid is supplied with the same flow rate and content in impurities bypassing the first separator in the second for another predetermined time interval required for the accumulation therein of sufficient dimensions for the quantity of collected impurities measured after the completion of which is the number of impurities and the separation factors calculated first and second separators are according to the formulas:

k ₁ is the separation coefficient of the first separator in the direction of the fluid;

k ₂ is the separation coefficient of the second separator along the fluid path;

V ₁₁ is the amount of impurity captured first in the direction of the fluid separator when the fluid is supplied to the first and second separator;

V ₂₁ is the amount of impurity captured by the second separator in the direction of the fluid when the fluid is supplied to the first and second separator;

V ₂₂ is the amount of impurity trapped by the second separator along the course of the fluid, when the fluid is supplied only to the second separator;

t ₁ is a predetermined time interval of fluid supply to the first and second separator;

t ₂ - a given time interval of the fluid supply only to the second separator.

It should be noted that the separation coefficient of the first separator can be determined independently of the characteristics of the second separator according to formula (1). In this case, the accumulation time of trapped impurities can be selected in such a way as to ensure the most optimal amounts of impurities to increase the accuracy of measurements. In addition, if there is no need to determine the separation coefficient of the second separator, the amount of impurities in the first separator can not be measured to speed up the work.

The method is implemented as follows.

A fluid containing impurities is fed into a pipeline to which two separators are connected in series with each other. Passing sequentially first through the first and then the second separators, the fluid is purified, and the captured impurities are collected in special containers. After a specified time, when the separators catch enough impurities, at the same time measure its amount on both separators. After that, the trapped impurity is removed from the separators.

Then, the first separator is turned off, and bypassing it, fluid is supplied with the same flow rate and the same impurity content directly to the second separator. After completing another predetermined time interval, when a sufficient amount of trapped impurity is accumulated in the second separator, its quantity is measured. The separation coefficients of the first and second separators are calculated by the formulas:

,

,

,

,

where k ₁ is the separation coefficient of the first in the direction of the fluid separator;

k ₂ is the separation coefficient of the second separator along the fluid path;

V ₁₁ is the amount of impurity captured first in the direction of the fluid separator when the fluid is supplied to the first and second separator;

V ₂₁ is the amount of impurity captured by the second separator in the direction of the fluid when the fluid is supplied to the first and second separator;

V ₂₂ is the amount of impurity trapped by the second separator along the course of the fluid, when the fluid is supplied only to the second separator;

t ₁ is a predetermined time interval of fluid supply to the first and second separator;

t ₂ - a given time interval of the fluid supply only to the second separator.

An example of a specific implementation of the method

At the well 3206 of the Bovanenkovo field, work was carried out to determine the characteristics of a separator stationary connected to the well, which is designed to measure the content of impurities (produced water, condensate, mechanical impurities) in the production of the well at various operating modes during gas-dynamic and gas condensate studies. In order to determine the proposed method, the separation coefficient at the end of the flare line of the well was installed collector "Nadym-1" [A.I. Gritsenko et al. Guide to well exploration. - M .: Nauka, 1995, p. 499], which includes a small-sized separator. Gas with impurities from the well was supplied to the first stationary separator, and then passed through a flare line to the second separator, which was part of the Nadym-1 collector. The well was put into operation at t ₁ = 3 hours in the regime with a flow rate of 535 thousand m ³ / day. The gas from the well containing impurities was supplied sequentially first to the first separator, and then to the second separator. Impurities removed from the gas were collected in special containers with which each of the separators were equipped. After the completion of the specified time interval, the well was switched to work in the gas gathering network with the same gas flow rate to exclude the influence of non-stationary processes during its shutdown and start-up. During this period, the contents of the separator containers were poured into a special measuring tank, with which the amount of trapped impurities in each separator was measured. The containers of the first separator contained V ₁₁ = 34 L of reservoir fluid, and the containers of the second separator contained V ₂₁ = 2.9 L of fluid.

After that, the first stationary separator was turned off, and the well was switched to flare line operation. At the same time, gas from the well bypassing the first separator via the bypass line entered through the flare line to the second separator (Nadym-1 collector). The well was put into operation at t ₂ = 1 hour in the same mode with a flow rate of 535 thousand m ³ / day. Then the well was stopped and the amount of reservoir fluid in the second separator was determined - V ₂₂ = 11 l.

By formulas (1) and (2), the separation coefficients of the first and second separators were calculated:

,

,

,

,

where k ₁ is the separation coefficient of the first in the direction of the fluid separator;

k ₂ is the separation coefficient of the second separator along the fluid path;

V ₁₁ is the amount of impurity captured first in the direction of the fluid separator when the fluid is supplied to the first and second separator;

V ₂₁ is the amount of impurity captured by the second separator in the direction of the fluid when the fluid is supplied to the first and second separator;

V ₂₂ is the amount of impurity trapped by the second separator along the course of the fluid, when the fluid is supplied only to the second separator;

t ₁ is a predetermined time interval of fluid supply to the first and second separator;

t ₂ - a given time interval of the fluid supply only to the second separator.

Thus, the proposed method allows to determine the separation coefficients of simultaneously two separators or only the first separator without the use of special measuring equipment, which reduces the cost of the work. At the same time, the possibility of selecting the intervals for the accumulation of impurities, first when two separators are working, and then only one, so as to ensure optimal volumes of impurities for measurement, increases the accuracy of the results. In addition, the measurement of the separation coefficients is carried out during the operation of the separators in real conditions, which also helps to increase the accuracy of the results, since there are no errors that arise when simulating real fluid flows.

Claims (10)

A method for determining the separation coefficient, comprising supplying an impurity fluid to two separators installed in series along its course, characterized in that the fluid is supplied to the separators for a predetermined period of time necessary to accumulate an amount of impurity captured by the separators for measurement, after which it is measured the amount of impurity in the first and second separators along the fluid path, and then the fluid is supplied with the same flow rate and impurity content in it, bypassing the first sep in the second during another predetermined time interval necessary for accumulating in it a quantity of trapped impurity sufficient for measurements, after which it is measured this amount of impurity and the separation coefficients of the first and second separators are calculated by the formulas:

where k ₁ is the separation coefficient of the first in the direction of the fluid separator; k ₂ is the separation coefficient of the second separator along the fluid path; V ₁₁ is the amount of impurity captured first in the direction of the fluid separator when the fluid is supplied to the first and second separator; V ₂₁ is the amount of impurity captured by the second separator in the direction of the fluid when the fluid is supplied to the first and second separator; V ₂₂ is the amount of impurity trapped by the second separator along the course of the fluid, when the fluid is supplied only to the second separator; t ₁ is a predetermined time interval of fluid supply to the first and second separator; t ₂ - a given time interval of the fluid supply only to the second separator.