Research On Downhole Data Acquisition And Processing Technology Of Intelligent Well

With the range of oil and gas exploration and development continues to expand,the reservoir environment is becoming increasingly complex.So the horizontal wells,extended-reach well,multi-lateral wells and other special structure wells are widely used to improve the efficiency of production.How to optimize these special structure well completion and production management have become an urgent problem of oil and gas production.However,the traditional completion method and production management mode has been unable to meet the needs of special structure well in production management and optimization.The research and development of intelligent well system and its related technology emerged in recent years provides a solution for this problem.It has gradually improved the oil and gas wells production management.At present,a number of intelligent well systems have been developed and used in oilfield by foreign oil companies.But there is no domestic self-developed intelligent well system.In this context,this paper research on theory and technology of intelligent downhole data acquisition,data processing and engineering application,and develop an intelligent downhole data acquisition and processing software platform based on previous research.The main research contents are as follows.Taking the three sections horizontal well as the goal,the overall design of the downhole data acquisition system is completed,and two sets of detailed design schemes are proposed.One plan is completely adopted equipments of Halliburton or Schlumberger.According to the specific situation of well completion structure,the selection of system equipment and key measuring components are supported.The other is a self-developed program.The detailed design of key components,such as the wellhead PDG module unit,wellhead device,signal transmission channel,PDG measuring device and mounting bracket,are self-developed.In order to overcome the deficiencies of the data processing method of intelligent well downhole pressure data,a complete,efficient and accurate data processing method is proposed.An absolute-deviation decision filtering method based on Hampel estimation is utilized to eliminate outliers of PDG pressure data.Wavelet analysis is used to reduce the noise of the data,and the conditional combination of wavelet threshold denoising is optimized through an orthogonal experiment.The pressure derivative method is used to identify the transients of pressure data.According to the different stages of the pressure change,the data are reduced by using the pressure and time thresholds,while the pressure threshold is used as the main factor,and the time threshold is used as a supplement.Based on the theory of hydrodynamics and the experimental platform of the intelligent well simulation system,the dynamic model of the influid control valve is studied,the flow pattern of the fluid passing through the valve hole is analyzed,and then the relationship between the influid control valve and the pressure difference is established.Based on the introduction of the relationship between the integrated flow coefficient and the ICV opening,a method for calculating the stratified rate of flow using ICV opening and PDG pressure is proposed.Assuming the reservoir is a linear system in a short time range and the reservoir model and other parameters are unknown,a new method of rate history calculation is proposed based on the PDG pressure and accumulative rate by using the transient well test interpretation theory and yield superposition principle.Based on the theory and method of support vector machine,the moving window technique is used to update the training set data in real time,the dynamic model is built according to the latest PDG data,and then realize the rate and pressure data rolling forecast.Based on the hydrodynamics numerical simulation,this paper studies the annulus and tubing pressure in different sections of the horizontal well when enchroachment ocurrs in different position,and puts forward a new method of monitoring the time and position of water invasion in horizontal well by using PDG pressure monitoring data.On the basis of the above theories and methods,this paper presents the overall structure and main function design of the Intelligent Well Downhole Data Acquisition and Processing System(IDDAPS),and achieved the system by using Microsoft Visual Studio.NET2003.The IDDAPS takes the PDG data as the core,uses the well station,the base and the enterprise thee levels of application pattern,take the data acquisition,data processing and engineering application as the main line.In short,this paper takes the intelligent downhole data as the center,studies the basic theories and implementation methods on the downhole data acquisition,processing and application,and discuses the key problems,such as PDG data acquisition,data processing,flow calculation and historical reconstruction,production and pressure prediction,then constructs and develops the intelligent well downhole data acquisition and processing software platform.An effective,realizable method is put forward for solving the key technical problems of intelligent well technology from aspects of the real-time monitoring,intelligent downhole data management,processing and application.On promoting the development of domestic intelligent well technology,improving the scientific management of production data of oil and gas,the accuracy of production decision-making,reducing production cost,and realizing the intelligent well and intelligent oil field,the research has important theoretical significance and application value.