A New Method For Phase-Regulated Volumetric Flow Measurement In Tight Oil Horizontal Wells

Tight reservoirs are characterized by low porosity and low permeability,so horizontal well development techniques are mainly used.In order to ensure the sustainable and stable production of horizontal wells and prevent the occurrence of water flooding,the oilfield is in urgent need of accurate output profile logging technology to provide technical support for horizontal well fracturing,water plugging and other production enhancement measures.However,the lower limit of the existing horizontal well output profile flow testing technology is high,and the accuracy of its testing technology is low,which is difficult to meet the demand of fine testing of tight oil horizontal wells.In order to solve the above problems,the following research is carried out in this paper:（1）This paper proposes a new phase-regulated volumetric flowmeter（PRVF）for lowproduction fluid horizontal wells,which can achieve accurate measurement of single-phase flow of oil and water by modal transformation.A two-dimensional simulation model of the phase-regulated rotating cavity is established.The finite element analysis software FLUENT is used to simulate the flow patterns of oil-water mixed fluid in the cavity under different modes,different water content and different flow rates.The flow pattern and state of the fluid in the cavity under different conditions are analyzed,and the regulation effect of the method is evaluated.The flow range applicable to this model is 1m³/d～10m³/d,which verifies the feasibility of this method.（2）In this paper,the structure of the array conductivity sensor（ACS）is optimized.A three-dimensional electric field simulation model of the phase-regulated rotating cavity is established using Comsol Muilipysics software,and the measurement mechanism of the probe array is analyzed qualitatively and quantitatively in terms of potential,electric field strength,and test sensitivity.The potential and electric field of the probe array under different structural parameters are qualitatively analyzed,and the structure of the probe array in the cavity is optimized according to the electric field range of the conductivity probe,and the conductivity probe structure with the most suitable electric field range for flow measurement is derived;The distribution characteristics of the spatial sensitivity of the conductivity probe with different structural parameters are quantitatively analyzed.The spatial sensitivity is analyzed by the average spatial sensitivity (S_avg)and the uniformity error parameter of the sensitive field(S_νp),and the optimal structure of the conductance probe is derived.（3）In this paper,the single-phase flow of oil and water are explained.For the PRVF designed in this paper,the responding laws in oil and water measurement modes were quantitatively analyzed,and the laws of the ACS response values with liquid level change in oil and water measurement modes are derived respectively,and then the accurate oil and water flow rates can be deduced.Finally,the dynamic simulation results are compared and analyzed with the static theoretical calculation results,and consistent results are obtained to verify the correctness of the single-phase flow measurement method for oil and water.