Improvement Of Coaxial Phase Water Meter And Design Of Piezoresistive Instrument For Low Yielding Liquid Wells

Chaoyanggou Oilfield belongs to the periphery blocks of Daqing Oilfield, whose oil reserves are low and undervoltage is significant. Developed reservoirs have low permeability, ultra-low permeability, and there is a huge difference about the physical properties, fluid properties and development condition among every reservoir, which leads to the difficulty of the output of the well. The production of the oil well is low, and is often accompanied by sand degassing and other problems. At present, annulus production profile logging tools mainly use umbrella collecting way to measure the flow rate and water cut, whose disadvantage is a large amount of leakage. The annulus production profile logging tools can’t measure the flow rate and water cut under the low flow accurately, and the measuring error of water cut is big. The turbine speed flowmeter and water cut measurement method in current use are difficult to meet output profile measurement for some special wells, so some new ways for solving these problems are urgent.The applicability of production profile logging technology in Chaoyanggou Oilfield is studied, and the instrument’s shortcomings are improved. After focusing on improving umbrella current collector for coaxial phase water meters, the ball current collectors with better collecting property are studied, and some field experiments for the effect of the improvement done. The result shows that the effect of complete flow pattern ball collector is superior to umbrella current collector in low yield liquid well. New piezoresistive type instrument is developed at the same time. It is a kind of power meter, which doesn’t have moving parts compared with the traditional turbine flowmeter. It is not only suitable for clean fluid measurement, but also can meet the requirements of fluid flow measurement with solid particles. And it not only can meet the requirements of water-drive output profile flow measurement, but also can complete polymer-drive output profile measurement with a viscous fluid properties. The application of the hanging low frequency dielectric water cut meter is simple and convenient, which can be installed in any needed position of the piezoresistive type instrument for output profile. The sensor response is only concerned with the water cut and not affected by water salinity. We don’t need to do down hole-sampling correction, which not only improve the efficiency of well logging and meet the requirements about measuring water cut under the low flow, but also improve the precision of production profile logging data and provide reliable technical support for the formulation of oilfield water flooding profile control scheme and oil well fracturing and water plugging etc. The research provides more accurate output profile data for the dynamic analysis of Chaoyanggou Oilfield, in order to improve its measurement precision and recovery efficiency ultimately. It will be a reference for low yield well testing in other oilfield, which has a very wide application range.