supercritical co 2 Flowmeter calibration device and calibration method thereof

Abstract

The invention relates to a supercritical CO2 flowmeter calibration device and a calibration method thereof, which are used for supercritical CO2 flowmeter calibration. A metering tank is arranged at the upper surface of a weighing device; a gas storage tank, a liquid pouring pump, the metering tank, a valve I, a liquid feeding pump, a booster pump, a heat exchanger, a surge tank, a valve III, a clamper, a throttle nozzle, a regulating valve II and a waste gas emptying device are sequentially connected by virtue of pipelines; one end of a valve II is connected with the gas storage tank, and the other end of the valve II is connected between the valve I and the liquid feeding pump. The calibration method comprises the following steps: closing the valves, regulating the regulating valve and mounting a flowmeter; regulating a gas nozzle; operating the heat exchanger; injecting liquid CO2 into the metering tank from the gas storage tank; opening the valve II, operating the liquid feeding pump and the booster pump, regulating the flow, and when the pressure reaches a designed value, opening the valve III; regulating the regulating valve II to enable the pressure to reach a calibration value; closing the valve II, opening the valve I, recording the mass and time of the metering tank, and calculating mass flow. The device is capable of realizing CO2 flow calibration under a supercritical environment.

Description

technical field [0001] The invention relates to the technical field of flowmeter calibration, in particular to supercritical CO 2 Flow meter calibration device and calibration method. Background technique [0002] Currently, by injecting CO into the formation 2 Oil flooding has been paid more and more attention by the industry. On the one hand, it is the need of oilfield development, and on the other hand, it is the need of reducing greenhouse gas emissions. CO 2 Oil displacement technology has been developed for many years, but the current gas injection technology is mainly all-well co-injection. Due to the difference in gas absorption capacity of formations, better oil displacement effect will be achieved by layered gas injection. In order to measure the gas injection volume of the stratification, downhole flowmeters are needed, however, the downhole flowmeters currently in use are not suitable for measuring CO 2 The flow rate, therefore need to develop specially for ...

AI Technical Summary

Problems solved by technology

This patented device is used to calibrate Super Pro CO 2 There are three problems in the flowmeter, one is that there is no temperature adjustment mechanism, and it cannot reach the supercritical CO 2 The second is that the experiment cannot be stabilized at one pressure for a long time. The device uses a pressure tank to provide gas, and uses a collection container and an adjustment container to recover the gas, and the pressure in the containers at both ends of the orifice plate drops and increases. cannot remain stable; 3, CO 2 It is generally stored in liquid state. If there is no booster pump behind the gas source container, the required calibration pressure cannot be obtained.

[0004] Chinese patent, application number 201310135827.9, application date 2013.04.19, patent name "a flow verification system and its verification method", discloses a calibration device that uses electronic weighing methods to measure flow, and has a temperature and pressure control system. The device is used to calibrate super-pro CO 2 The flowmeter also has the following problems: First, this is a closed-loop circulation device, and it is no problem to use water as the calibration medium, but CO 2 The storage tank is liquid, and the CO after calibration is completed 2 It is gas and cannot be recycled; second, the pressure stabilizing system of the device is to set up a gas space on the upper part of the water container, and adjust the pressure in the water container through an air pump, while CO 2 It is also a gas itself, and the two gases will mix when they meet, so it is not suitable for CO 2 The pressure stabilization of the calibration device; three, the constant pressure device of the device only produces a stable flow rate, and after the water flows out of the water container, it basically becomes normal pressure at the position of the flow meter, while the CO 2 Supercritical pressure is required at the flowmeter, so this device cannot achieve it either

[0005] The standard measurement method adopted by the above two published patents is to collect the fluid and weigh it after the flowmeter is calibrated, because supercritical CO2 is difficult to recover, so the above weighing method is not suitable for CO 2 Flow Calibration Device

Images