The Thermal Trace Method For Measurement Of The Flowrate In A Low Production Horizontal Well

With the deepening of oil and gas exploration and development, most of our oil fields have been developed to mid-stage or late of the exploitation, low-permeability, heavy crude and high pour point crude production wells continue to emerge. Horizontal wells can increase production capacity of oil and gas wells, be suitable for low permeability, low pressure, heavy crude exploitation and other types of reservoirs, so high production can be achieved in yield thin wells, development costs can be reduced. Compared with vertical wells, horizontal wells have more complex pattern due to gravity fluid flow, it will impact on the measurement and interpretation. Subject to, up and down the logging equipment become more difficult than vertical wells for restrictions on measurement channels of horizontal wells, in addition, the level of the well cuttings and debris in the horizontal wells can easily enter the measuring instruments, so impact on the measurement results. Therefore, the success rate of the logging instrument and its reliability are need to be improved.In recent years, turbine flow meter is mainly used for production profile logging of horizontal wells while collecting fluid in the country. When turbine flow meter is measuring the low flow, the turbine is easily stuck by sand, at the same time, the low success rate is reduced. Therefore, this paper proposes a thermal tracer measurement of oil-water two-phase flow method, it has no moving parts, no radiation, no pollution, high reliability, the method can measure for a long time.The paper introduces the basic structure and flow measuring principle of the thermal trace flow meter, the temperature field of the sensor in flow meter is simulated by simulation software FLUENT, the simulation is only water phase under different flow and different heat power, according to the changes of temperature inside the sensor, the best placement of sensors is obtained and it provides the reference for processing the experimental prototype. The experimental prototype of thermal tracer flow meter is designed and fabricated, dynamic experiment is done on the multiphase flow in horizontal wells experimental system. The results show that the temperature signal curves from the temperature sensor are well, and relevant. By processing the experimental data using correlation algorithm, the average correlation flow rate of the different water flow rates has good linear relationship with the standard flow rate, it has a resolution between 3 m3/d with 30m3/d,the results illustrate this method can be applied to flow measurement in horizontal well.