WANG Xiaomei ，YU Zhongsheng，DING Youqing，ZHU Xincai

1.Chongqing University of Science and Technology，Chongqing 401331，China;2.Chongqing University of Technology，Chongqing 400054，China

1.Introduction

The heavy oil exploitation is complex and high cost，and there are many rules have not been mastered.Heavy oil is Non-newtonian fluid.Its physical and chemical flow regularity is quite complex.Multiphase flow model used in engineering currently is obtained through thin oil(Newtonian fluid)flows based on the low pressure test or field test conditions.The model does not apply to heavy oil flow regularity.Therefore，experimental research in this field is an urgent need.It is necessary to develop a new experimental device to provide a scientific basis for understanding the mechanism and laws of heavy oil flow.This paper briefly introduces the structure design of a heavy oil wellbore lift simulation experiment device.

2.Structure of heavy oil wellbore lift simulation experiment device

The wellbore lift simulation experiment device is designed to be a modular small test simulation device.It consists of four parts，including mixing shear module module，module and circular pipe flow circulation module.

Each code illustrated in Fig.1 is shown in Table 1.

Fig.1 Basic structure of the experiment device

3.Characteristics of experiment device

The experimental device has the following features:

1)It can simulate the actual pumping process flow condition.The actual production process is a one-way fluid flow.

2)It realizes the cycle，avoids the dead zone，makes the mix more evenly and higher efficiency，and accords with the real condition.Especially because the static mixer requires one-way flow，it is dif-ficult to evaluate its characteristics if it uses reciprocating driving.

3)Due to the realization of circulation，it makes the heating insulation of the whole system more uniform.

4)The vertical lifting test process is more stable and can be repeated many times，which gets more accurate data.

5)Feeding and sampling are not affected by the volume effect，which is very convenient.

Tab.1 Illustration of each code

4.Instructions of experimental process

1)Experiment preparations

The heavy oil and treatment agent are respectively put into reservoir T2 and T3，and they are put in test requirements for heating and stirred to spare.The purpose of these preparations is to ensure that heavy oil has good fluidity，otherwise the metering pumps can not work normally.

2)Heavy oil flow test

①According to the set proportion to start metering pumps C1 and C2，heavy oil and treatment agent are mixed into reservoir T1.

② The test fluid is heated，stirred and mixed in T1，until it is mixed evenly.

③ Open the manual globe valves F3，F(xiàn)4(or F1，F(xiàn)2)and the electric globe valves K1，K2，and then open the manual globe valve F5 to make the test liquid flow down into the test piping and piston pump cylinder.

④Start the stepping motor DK.At the same time，respectively control the electric globe valves K1 and K2 on or off.It can make fluid in the pipe line further circulation process，and detect parameters until the mixed liquid meets the testing requirements.

⑤Test flow parameters of fluid in measuring section，including differential pressure in measuring section，total pressure in vertical section and fluid flow pipeline etc.And record the related data and test curve，until it reaches the experiment requirement.

⑥ Calculate the test results，analyze the related results，and display and print the test results report.

Note:According to the specific needs in the process of the flow test，respectively make the liquid flow through or not through the mixer.So simulate the actual working condition in the process of pumping which install underground mixer or not，and then make the related evaluation.

Mixture flows into lift module after single or multiple flows through the pump.In lift module，mixture liquid column can move up and down under the control of reciprocating pump，and related flow parameters are obtained through the measuring section.

Each module has its own test system，circulation system and temperature control system，can be run separately and determine the operating effects of various components，and can also analyze the overall effect of the wellbore lift after each module combination.And the corresponding facilities can realize the overall circulation.

3)Mixer flow testing experiment

①According to the set proportion to start metering pump C1 and C2，heavy oil and treatment agent are mixed into reservoir T1.

② Open the manual globe valves F3，F(xiàn)4 and the electric globe valves K1，K2，and then open the manual globe valve F5 to make the test liquid flow down into the test piping and piston pump cylinder.

③Start the stepping motor DK.At the same time，respectively control the electric globe valves K1 and K2 on or off.Pump mixed liquid to observation window G3 height position so far.

④ Shut down electric globe valve K2，and then start stepping motor/piston pump.According to the experiment requirements，make the mixture reciprocating flow through the mixer a certain number of times，and record related parameters(differential pressure in mixer section).At the same time，take the sample，analyze and evaluate the liquid mixing effect under the corresponding number of mixed times by open valve F6.

⑤Contrast and analyze the test results and the mixed effects，display and print the test results report.

Note:The mixed effect of mixer can also be evaluated directly by circulation flow test of mixing liquid under the same conditions.

4)Clean the test system.

①Open the manual globe valve F6 for the fluid discharge.

② Start metering pumps C1 and C2，and pump the residual heavy oil and the treatment agent into reservoir T1，then the mixture is discharged from valve F6.

③Add detergent respectively into the heavy oil reservoir T2 and the treatment agent reservoir T3，and carry out stirring and cleaning.

④ Close the manual globe valve F6，and then start metering the pumps C1 and C2.Mix the detergent into the mixture reservoir T1，and start stirrer and piston pump repeated cyclically to clean the entire pipeline.

⑤Open the manual globe valve F6 to make all detergent mixture flow out.

Note:The cleaning process can be repeated several times until the system pipelines and reservoirs are cleaned up basically.

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