Chunhui Huang

Conductance Sensor for Measurement of the Fluid Watercut and Flowrate in Production Wells

A new type of conductance sensor is designed to measure both the flowrate and the water cut simultaneously in oil/water two phase flow in oil production wells. With the conductance sensor, the watercut is obtained by the ratio of the conductivity of the oil/water mixture to that of the water, and the flowrate is gotten by cross‐correlation flowrate measurement, which can figure out the transit time of the fluid flowing noises passing through the upstream and downstream sensors in the conductance sensor. In the paper, the principles of measuring flowrate and watercut are introduced. The results of dynamic experiment in multiphase flow loop and the application in field of the technology are introduced in it too.

Novel Downhole Electromagnetic Flowmeter for Oil-Water Two-Phase Flow in High-Water-Cut Oil-Producing Wells

First, the measuring principle, the weight function, and the magnetic field of the novel downhole inserted electromagnetic flowmeter (EMF) are described. Second, the basic design of the EMF is described. Third, the dynamic experiments of two EMFs in oil-water two-phase flow are carried out. The experimental errors are analyzed in detail. The experimental results show that the maximum absolute value of the full-scale errors is better than 5%, the total flowrate is 5–60 m3/d, and the water-cut is higher than 60%. The maximum absolute value of the full-scale errors is better than 7%, the total flowrate is 2–60 m3/d, and the water-cut is higher than 70%. Finally, onsite experiments in high-water-cut oil-producing wells are conducted, and the possible reasons for the errors in the onsite experiments are analyzed. It is found that the EMF can provide an effective technology for measuring downhole oil-water two-phase flow.

Novel Four-Electrode Electromagnetic Flowmeter for the Measurement of Flow Rate in Polymer-Injection Wells

In this article, a novel four-electrode electromagnetic flowmeter (EMF) is proposed for flow rate measurement in polymer-injection wells. The ideal response model of the four-electrode EMF is established. In this model, the weight function and intensity of magnetic field are both derived, according to which numerical calculations are conducted. The calculation results show that in the annular area between the flowmeter and oil tubing, the weight function and magnetic field are both symmetrically distributed near the measurement electrodes and magnetic poles, respectively, and are rapidly attenuating along the radius direction. The potential difference is calculated for several kinds of flow velocity profiles in the annular area, and the calculation results show that the output of the four-electrode EMF is sensitive to the distribution of the flow profile. The experimental results obtained by using the multiphase flow loop facility show that when the four-electrode EMF is used in polymer solutions, the instrument constant of the four-electrode EMF differs from that used in tap water and remains unchanged with the concentration of the polymer solutions. The flow patterns of tap water and polymer solutions are various, leading to the change of the instrument constant of the four-electrode EMF. On-site experiments show that the four-electrode EMF is suitable for the polymer-injection wells developed in short durations. For the wells developed in long durations, the four-electrode EMF is limited because of the contamination, distortion, and corrosion of the oil tubing.

A new method of measuring the oil-air-water three-phase flow rate

Abstract Oil–air–water three-phase flow patterns in small-diameter vertical measurement channels are complex, making it difficult to establish techniques for interpretation of logging information. In this study, dynamic experiments involving oil–air–water three-phase flows were performed using a novel production logging tool that combined a petal-type turbine flowmeter, a conductance sensor, and an optical fiber sensor in a simulation well. Sensor response characteristics were researched, and a new method of measuring the oil–air–water three-phase flow rate was proposed. The measurement range and resolution of the gas flow rate were 3–20 and 1 m3/d, respectively, and the relative error range of gas flow rate interpretation was 5–10%. The measurement range and relative interpretation error range of the total liquid flow rate were 10–60 m3/d and 5–10%, respectively. The measurement range and resolution of the water cut were 50–100% and 2%, respectively. The absolute error range of interpretation of the water cut ranged from 3.2% to 5%. Currently, the technique is valid for laboratory use under ideal conditions.

The response of combined capacitance sensor in the horizontal condition

For measurement of the water-cut of the fluid in a low production horizontal well, a combined capacitance sensor is designed which is composed of the cylindrical capacitance sensor and the coaxial capacitance sensor. The two sensors are of parallel connnection in the electric circuit. Because of parallel connnection of the two capacitance sensors, the surface area of the combined sensor increases. Thus in the non-stratified flow, the oil bubbles are apt to touch the sensor and its measurement resolution is improved. And in the stratified flow, the cylindrical capacitance which plays a leading role is sensitive to the hight of oil-water interface. The structure of the sensor is introduced in the paper. The electric field simulation is conducted and the sensor response in the oil/water stratified flow and bubble flow are given. Static experiment and dynamic experiment of the sensor are carried out and the response at the different flowrate and water cut is obtained. The results show that the combined capaci...