Imaging Of Oil-Water Two-phase Flow In Horizontal Wells Based On MAPS

With the widespread application of horizontal wells and highly deviated wells in offshore oilfields,the accompanying production problems have gradually emerged.Among them,the problem of water cut rising is the most obvious,which seriously restricts the application effect of horizontal well exploration and development.Water search technology of horizontal well in oilfield is one of the key problems to be solved during the 13 th Five-Year Plan period.Horizontal well water prospecting is different from conventional straight and inclined wells in terms of basic theory,logging tools and interpretation and evaluation methods.The domestic research on horizontal well logging technology is still in its infancy.In order to meet the needs of interpretation and evaluation of production logging in domestic horizontal wells,reduce the cost of software upgrade and form a competitive advantage in overseas markets and operations in the future,it is urgent to establish a set of related theory and practical technology of water prospecting in horizontal wells to meet the needs of actual production.The new generation of array imaging logging tool MAPS(Multiple Array Production Suite)developed by GE company provides advanced equipment support for multiphase flow detection and analysis in horizontal wells.The core of MAPS technology includes three downhole arrays,namely Capacitance Array Tool,Resistance Array Tool and Spinner Array Tool.For multi-phase flow of oil,gas and water in horizontal wells,three different signals are generated by each sensor to reflect the three-phase holdup and flow rate respectively.According to the measured values of each sensor,the volume and flow rate of each phase can be restored through the processing of computer analysis software,so that the flow pattern in horizontal wells can be more truly reflected.At the same time,the special software can be matched to reflect the flow pattern in horizontal wells.The logging results are restored to simulated images.In this paper,the instrument structure and principle of MAPS are introduced in detail.Aiming at the application of MAPS in horizontal wells,flow rate experiment and holdup experiment are carried out in the production logging Laboratory of Yangtze University.Under the condition of horizontal and near horizontal wells,the downhole oil-water two-phase situation is simulated.The fluid flow of MAPS in oil-water two-phase flow in horizontal wells is analyzed,and the flow pattern distribution of oil-water two-phase flow in downhole horizontal wells can be obtained by this simulation method.The start-up flow rate and turbine sensitivity of SAT are analyzed,and the accuracy of holdup measured by CAT and RAT are compared and analyzed.At the same time,the oil-water two-phase flow patterns in horizontal wells are identified and different flow patterns are classified.The software of oil-water two-phase flow holdup imaging in horizontal well matched with array sensor CAT and RAT in MAPS instrument is developed.The distribution pattern of each phase of downhole fluid is given through the interpretation of imaging processing,so as to identify the flow pattern and determine the content of each phase.It provides reliable and accurate basis for reservoir dynamic analysis and production situation of each well.MAPS imaging software is mainly divided into two modules,namely two-dimensional imaging module and three-dimensional imaging module.Firstly,the software can import and select the data,and choose the calculation method of different water holding capacity according to the instrument of MAPS used;choose different interpolation methods and depth to interpolate and image the cross section of wellbore;including 12 local water holding capacity of array sensor CAT and RAT;the two-dimensional imaging module is mainly responsible for two-dimensional imaging,mainly by inverse distance ratio weighted interpolation,Gauss radial basis function.Function interpolation and Kriging interpolation are three algorithms for imaging.The three-dimensional imaging module is mainly the downhole three-dimensional wellbore imaging,which can reflect the downhole oil,gas and water flow in a certain depth range through the input depth range,and can carry out three-dimensional rotation.Combined with the experience of interpreters,the imaging interpretation results are synthesized.It provides a reference for subsequent log interpretation.