CN1038067C - Oil, gas and water mixed transportation indexing method - Google Patents

Abstract

An oil, gas and water mixed transportation dividing method with water content of 5-100% comprises selecting a pipe diameter of 200-1500mm under the condition that the gas-liquid ratio is 200%, setting the density of oil, gas and water in the density range, sampling to calibrate the density of mixed liquid, further calculating the liquid level height by the linear density measured by a radiation source and a receiver which are vertical to the axis, measuring the volume of the oil, gas and water lines by a volume flowmeter, pure oil, water and gas are measured by an oil, gas and water mixed transportation dividing device designed according to the functional relation among the linear density, the liquid level height, the linear volume, the pipe diameter and the gas, oil and water parameter quantity density, the error of the pure oil measured by the measuring method is as small as 2 percent, and a water content analyzer is omitted in the measurement, so that the concept that oil, gas and water cannot be separately measured in a mixed transportation state and the concept that pure quantity errors cannot be reduced in high water content transportation which are considered by people for a long time are overcome.

Description

Oil, gas and water mixed transportation indexing method

The invention relates to a mixed transportation indexing method capable of separately metering high water content oil, gas and water.

In the existing technology, in the case of high water content, the method of dividing oil, gas and water mixed transportation is: a. First, directly measure the water content signal through the instrument, or use the formula: $f_w=\frac{{\mathrm{\ρ}}_w({\mathrm{\ρ}}_{\mathrm{ow}}-{\mathrm{\ρ}}_o)}{{\mathrm{\ρ}}_{\mathrm{ow}}({\mathrm{\ρ}}_w-{\mathrm{\ρ}}_o)}$ In the formula, ρ _ow is the density of the mixed liquid, ρ _w is the density of water, and ρ _w is the density of oil. By measuring the linear density values of oil, gas and water, the linear density value ρ _x replaces the mixed liquid density ρ _ow in the formula to calculate the water cut value f _w , the oil quantity formula M _o =ρ _ow V _OW (1-f _w ) measures the pure oil quantity by the metering device, of course, the linear density ρ _x is used to replace the mixed liquid density, and the linear volume V _x is used to replace the mixed liquid volume V _ow , b, the main error of pure oil measured in this way is: ${\mathrm{\δ}}_{\mathrm{mo}}=\frac{{\mathrm{\δ\; f}}_w}{1-f_w}$ In the process of obtaining the water cut value f _w , the linear density is used instead of the mixed liquid density, resulting in a large error in the water cut value, resulting in a large error in pure oil volume and inaccurate oil volume measurement. When the gas-liquid ratio GLR is 50%, the error of the pure oil amount can reach 12%, and the error of the pure oil amount can reach 11% when the gas-liquid ratio GLR is 20%. When the pure liquid is delivered, the water content is ≥95%. , The error of pure oil amount is up to 10%.

The purpose of the present invention is to provide a method for more accurate graduation of pure oil, water and gas in the state of mixed oil, gas and water with a water content of 5-100%.

The key of the present invention is to adopt a kind of measuring method of pure oil quantity irrelevant to water content, concrete measuring method is as follows: a, at first when vapor-liquid ratio is within 200%, choose pipe diameter d to be 200-1500mm, at 0.0004-0.0007 Set the gas density ρ _g within the gas density change range of ton/ ^m3 , set the ton oil density value ρ _o within the range of 0.8369-0.8398 ton/ ^m3 pure oil density change value, and set the ton oil density value ρ o within the range of 0.9943-0.9977 ton/m Set the water density value ρ _w within the range of the water density change value of ³ , b, the sampling calibration mixed liquid density ρ _vw , c, the linear density ρ _x measured by the radiation source 1 and the receiver 2 perpendicular to the axis of the horizontal pipeline, and further pass according to ${\mathrm{\ρ}}_{\mathrm{ow}}=\frac{d\left({\mathrm{\ρ}}_{x\_}{\mathrm{\ρ}}_g\right)+{\mathrm{\ρ}}_{g}h}{h}$ Calculate the liquid level height, d, measure the linear volume V _x of oil, gas, and water through the volumetric flowmeter 3, e, pass the linear density ρ _x , liquid level height h, linear volume V _x , pipe diameter d and gas, oil, The Functional Relationship of Three Parameter Quantities Density ρ _g , ρ _o , ρ _w of Water $m_o=\frac{h}{d}\&Center\; Dot;V_x\&Center\; Dot;{\mathrm{\ρ}}_g\·\frac{h{\mathrm{\ρ}}_x-d({\mathrm{\ρ}}_w-{\mathrm{\ρ}}_g)-h{\mathrm{\ρ}}_g}{h({\mathrm{\ρ}}_w-{\mathrm{\ρ}}_g)}$ $V_g=V_x(1-\frac{({\mathrm{\ρ}}_o-{\mathrm{\ρ}}_g)h}{d({\mathrm{\ρ}}_x-{\mathrm{\ρ}}_g)+{\mathrm{\ρ}}_{g}h})$ $V_w=V_x-V_g-\frac{m_o}{{\mathrm{\ρ}}_g}$ The designed oil, gas and water mixed delivery indexing device 4 measures the pure oil volume, water volume and gas volume.

The error of measuring the pure oil quantity in this way is only related to five variables, namely liquid level height h, density ρ _v , ρ _g , ρ _w of oil, gas and water, and linear volume V _x . Among the above five variables, The change value of gas density is within the range of 0.0004-0.0007 tons/ ^m3 , the change value of pure oil density is within the range of 0.8369-0.8398 tons/ ^m3 , and the change value of water density is within the range of 0.9943-0.9977 tons/ ^m3 , the liquid level is high because the calibration mixed liquid density ρ _ow is a constant, so there is an error of 5mm, and the linear volume uses a 0.2-level volume meter, so there is an error of 0.5%. The errors caused by complex factors such as mining and transportation of heavy oil, thin oil, and high pour point oil are all included in the above error range. The error calculated by taking the error extreme value of any of the above five variables and performing 32 error drifts is 2%. , the present invention only uses one piece of oil, gas, and water mixed transport indexing device, saves one water cut analyzer, and makes the error of pure oil volume independent of the water cut value, thereby overcoming the long-standing problem that people think that oil, gas, and gas are mixed in the state of mixed transport. 1. The concept that water cannot be measured separately and high water content transportation cannot reduce the error of pure oil.

The technical solutions of the present invention will be described in detail below in conjunction with the accompanying drawings.

Fig. 1 is a diagram of a pipeline component of the present invention.

Example 1:

As shown in Figure 1, the oil, gas, and water mixed transport indexing method of the present invention is special in that a, firstly, when the vapor-liquid ratio is 200%, the pipe diameter d is selected to be 720mm, and the gas density _pg is set to be 0.0005 ton/ ^m3 , set the pure oil density value ρ _g to 0.8369 ton/ ^m3 , set the water density value _ρw to 0.9943 ton/ ^m3 .b, and calibrate the mixed liquid density _ρvw by sampling. c. The linear density ρ _w measured by the radiation source 1 and the receiver 2 perpendicular to the axis of the horizontal pipeline, and further passed according to ${\mathrm{\ρ}}_{\mathrm{ow}}=\frac{d\left({\mathrm{\ρ}}_{x\_}{\mathrm{\ρ}}_g\right)+{\mathrm{\ρ}}_{g}h}{h}$ Calculate the liquid level height, d, measure the linear volume V _x of oil, gas, and water through the volumetric flowmeter 3, e, pass the linear density ρ _x , liquid level height h, linear volume V _x , pipe diameter d and gas, oil, The Functional Relationship of Three Parameter Quantities Density ρ _g , ρ _o , ρ _w of Water $m_o=-V_x\underset{d}{\overset{h}{{\mathrm{\ρ}}_o}}\frac{h{\mathrm{\ρ}}_w-d\left({\mathrm{\ρ}}_{x\_}{\mathrm{\ρ}}_g\right)-h{\mathrm{\ρ}}_g}{h({\mathrm{\ρ}}_w-{\mathrm{\ρ}}_o)}$ $V_g=V_x(1-\frac{({\mathrm{\ρ}}_x-{\mathrm{\ρ}}_g)h}{d({\mathrm{\ρ}}_x-{\mathrm{\ρ}}_g)+{\mathrm{\ρ}}_{g}h})$ $V_w=V_x-V_g-\frac{m_o}{{\mathrm{\ρ}}_o}$ The designed oil, gas and water mixed delivery indexing device 4 measures the pure oil volume, water volume and gas volume.

The error of calculated pure oil amount is 2%.

Example 2:

As shown in Figure 1, the oil, gas and water mixed transmission indexing method of the present invention is special in that a, firstly when the vapor-liquid ratio is 200%, the pipe diameter d is selected as 1500mm, and the gas density _ρz is set to be 0.0005 ton/ ^m3 , set the pure oil density value _ρg to 0.8369 ton/m3, set the water density value to 0.9943 ton/ ^m3 , b, sampling and calibration mixed liquid density _ρow , c. radiation through the vertical and horizontal pipeline axis The linear density ρ _x measured by source 1 and receiver 2 is further passed according to ${\mathrm{\ρ}}_{\mathrm{ow}}=\frac{d\left({\mathrm{\ρ}}_{x\_}{\mathrm{\ρ}}_g\right)+{\mathrm{\ρ}}_{g}h}{h}$ Calculate the liquid level height, d, measure the linear volume V _x of oil, gas, and water through the volumetric flowmeter 3, e, pass the linear density ρ _x , liquid level height h, linear volume V _x , pipe diameter d and gas, oil, The Functional Relationship of Three Parameter Quantities Density ρ _g , ρ _o , ρ _w of Water $m_o=\frac{h}{d}{V}_x{\mathrm{\ρ}}_o\frac{h{\mathrm{\ρ}}_w-d\left({\mathrm{\ρ}}_{x\_}{\mathrm{\ρ}}_g\right)-h{\mathrm{\ρ}}_g}{h({\mathrm{\ρ}}_w-{\mathrm{\ρ}}_o)}$ $V_g=V_x(1-\frac{({\mathrm{\ρ}}_x-{\mathrm{\ρ}}_g)h}{d({\mathrm{\ρ}}_x-{\mathrm{\ρ}}_g)+{\mathrm{\ρ}}_{g}h})$ $V_w=V_x-V_g-\frac{m_o}{{\mathrm{\ρ}}_o}$ The designed oil, gas and water mixed delivery indexing device 4 measures the pure oil volume, water volume and gas volume.

The error of calculated pure oil amount is 1.8%.

Claims (1)

1. A method for dividing oil, gas and water mixed transportation with a water content of 5-100%, characterized in that a. First, when the gas-liquid ratio is within 200%, select the pipe diameter d to be 200-1500mm, and set the gas density ρ _g within the range of gas density variation of 0.0004-0.0007 tons/ ^m3 , and set the gas density at 0.8369-0.8398 tons Set the pure oil density value ρ _o within the range of the pure oil density change value per m3, and set the water density value ρ _w within the range of the water density change value of ^{0.9943-0.9977} tons/ ^m3 , b. Sampling and calibration mixed liquid density ρ _vw , c. The linear density ρ _x measured by the radiation source 1 and the receiver 2 perpendicular to the axis of the horizontal pipeline, and further passed according to ${\mathrm{\ρ}}_{\mathrm{ow}}=\frac{d\left({\mathrm{\ρ}}_{x\_}{\mathrm{\ρ}}_g\right)t{\mathrm{\ρ}}_{g}h}{h}$ Calculate the height of the liquid level, d. Measure the linear volume V _x of oil, gas and water through the volumetric flow meter 3 . e. The functional relationship of density ρ g , ρ _o , and ρ _w through linear density ρ _x , liquid _level height h, linear volume V _x , pipe diameter d, and gas, oil, and water parameters: $m_o-\frac{h}{d}{V}_x{\mathrm{\ρ}}_g\frac{h{\mathrm{\ρ}}_w-d\left({\mathrm{\ρ}}_{x\_}{\mathrm{\ρ}}_g\right)-h{\mathrm{\ρ}}_g}{h({\mathrm{\ρ}}_w-{\mathrm{\ρ}}_o)}$ $V_g-V_k(1-\frac{({\mathrm{\ρ}}_x-{\mathrm{\ρ}}_g)h}{d({\mathrm{\ρ}}_x-{\mathrm{\ρ}}_g)+{\mathrm{\ρ}}_{g}h})$ $V_w=V_x-V_g-\frac{m_o}{{\mathrm{\ρ}}_o}$ The designed oil, gas and water mixed delivery indexing device 4 measures the pure oil volume, water volume and gas volume.

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