RU2307246C2 - Method for production output measurement in pressure-sealed gathering systems - Google Patents

Abstract

FIELD: oil production, particularly active estimation of oil and gas-condensate wall production rate in pressure-sealed gathering facilities.

SUBSTANCE: method involves filling measuring vessel having calibrated volume with well product for time period defined with taking into consideration of maximal device efficiency with gas pipeline communicated with manifold and with closed fluid discharge pipeline; stopping well product supply into measuring vessel at the expiration of the time period; measuring fluid column height, hydrostatic pressure and temperature; calculating fluid, oil, water output; continuing well product delivery into measuring vessel with closed gas pipeline and liquid pipeline communicated with manifold; determining measuring vessel unloading rate and excessive pressure; calculating gas output; determining water content in well product contained in measuring vessel by setting thereof up to foam settling and absence of gas bubbles only in 2% of total measurement amount; performing remainder measurements for output determination after receiving of stable fluid-gas interface surface height readings or measurements are performed without setting operation if possible.

EFFECT: decreased measurement cycle duration along with increased foam-generation and well output.

Description

The invention relates to oil production and can be used for operational accounting of production rates of oil and gas condensate wells in pressurized collection systems.

There is a known method of accounting for oil well production, according to which the time for filling a measuring tank of a fixed volume with partially separated well products is determined with a gas line and a closed drain liquid line open to the collector, hydrostatic pressure is determined at a known height of the liquid column, overpressure, temperature, rate of displacement of the contents of the container after closing the gas line and opening the drain fluid line to the manifold and calculate the performance of liquid ti, oil, water and gas based on the received data and the known densities of the formation water and oil contained in the well stream [1].

The disadvantages of this method are:

- low accuracy and instability of measurements with increased foaming and high flow rates of wells;

- very stringent requirements for the quality of separation;

- high material consumption of the device, due to the need to have a very powerful separator.

The closest technical solution is a method for measuring the production rate of oil wells in pressurized-gathering systems, namely, that the measuring capacity of the calibrated volume is filled with well products for a predetermined time taking into account the maximum productivity of the device when the gas and closed drain lines are open to the collector, after the specified time, the flow of well products into the measuring tank is stopped, well production, containing which is contained in the measuring vessel, is held up to the state of foam subsidence and the complete absence of bubble gas, then the height of the liquid column is measured, hydrostatic pressure and temperature are calculated, the productivity of liquid, oil and water is calculated based on the data obtained and the known densities of oil and produced water contained in well production, and then simultaneously with the closure of the gas and the opening of the liquid lines to the reservoir, the flow of well production into the measuring tank is resumed and, having determined the speed of emptying the measuring capacity and gauge pressure, calculate the performance of gas [2].

The disadvantages of the known method and device include the significant length of the measurement cycle with large foaming and high flow rates of wells.

The objective of the proposed technical solution is to reduce the duration of the measurement cycle with large foaming and high flow rates of wells.

To achieve the technical result in a method for measuring the production rate of oil wells in pressurized-gathering systems, including filling the measuring capacity of the calibrated volume with well products for a predetermined time taking into account the maximum productivity of the device with open gas and closed drain liquid lines to the collector, stopping the flow of well products into the measuring tank after the appointed time, keeping the production of wells the information contained in the measuring tank to the state of foam subsidence and the complete absence of gas bubbles, measuring the height of the liquid column, hydrostatic pressure and temperature and calculating the flow rate for liquid, oil and water, resuming the flow of well products into the measuring tank while closing the gas and opening the liquid lines to the collector, determining the rate of emptying of the measuring capacity and gauge pressure and calculating the gas rate according to the invention for determining the water content of products with the wells contained in the measuring vessel can withstand to the state of foam subsidence and the complete absence of bubble gas in only two percent of the total number of measurements, and the remaining measurements are determined by flow rate determination after stable readings by the level gauge of the liquid-gas interface or, if possible determining the height of the interface between the phases "liquid - gas" - without aging.

The proposed method can significantly reduce the duration of the measurement cycle with large foaming and high flow rates of wells without compromising the quality of the measurements, since the mass of liquid contained in the measuring tank can be determined without deep sludge (aging) - if only the level gauge “grasped” the phase interface liquid - gas ", and the water content, for the correct measurement of which deep sludge is necessary, does not require frequent checks, since it changes slowly during the operation of the well.

The method is implemented as follows.

When determining the production rate of oil wells by the hydrostatic method, the production of the well is maintained to the state of foam subsidence and the complete absence of bubble gas (deep sludge) is carried out on only a small part of the measurements, for example, one out of fifty. At the same time, the completion of sludge is judged by the end of the change in the readings of the level gauge.

All other measurements of the production rate of oil wells are made immediately after the level gauge has steadily shown the height of the liquid-gas interface.

Deep sediment in different fields can last from several minutes to many hours. Using the proposed technical solution will significantly reduce the duration of the average measurement cycle with large foaming and high flow rates of wells and reduce the methodological error due to the discontinuity (non-continuity) of the measurement process.

Information sources

1. RU 22179 U1, Cl. ЕВВ 47/00, 03/10/2002.

2. RU 2220282 C1, Cl. ЕВВ 47/10, 12/27/2003.

Claims (1)

A method of measuring the production rate of oil wells in pressurized collection systems, including filling the measuring capacity of the calibrated volume with the production of the well for a predetermined time taking into account the maximum productivity of the time device with open gas and closed drain lines, stopping the flow of well products into the measuring tank after the designated time, maintaining the production of the well contained in the measuring tank to a state of foam and the complete absence of gas bubbles, measuring the height of the liquid column, hydrostatic pressure and temperature and calculating the flow rate of liquid, oil and water, the resumption of well production in the measuring tank while closing the gas line and opening the liquid line to the collector, determining the speed of emptying the measuring tank and excess pressure and gas flow rate calculation, characterized in that for determining the water content of the well products contained in the measuring tank, withstanding t until the foam settles and the bubble gas is completely absent only in two percent of the total number of measurements, and the remaining measurements are determined by the flow rate after stable readings by the level gauge of the height of the liquid-gas interface, or if it is possible to determine the height of the liquid interface gas "- without aging.