Study And Application Of Method For Wire Line Formation Test

Drill stem test(DST)can evaluate the reservoirs timely and accurately.The design of the test procedure mainly depends on empirical knowledge and human subjectivity,specially relies on permeability which is achieved from core analysis and logging,however there is big difference between the figures which are mentioned above and the one which can stand for the actual figure from the reservoir diffusion.This thesis studied the flow mechanics during wireline formation test and the methods of optimal design for DST,the permeability which is achieved from wireline formation test interpretation can be applied to the optimal design of DST.This project can be divided into four parts.Firstly,the researchers studied and analyzed the flow mechanics during wireline formation test,constructed and solved the mathematical model of spherical flow and radial flow,drew the pressure and pressure derivative curves and then analyzed the characteristics and influencing factors of the curves.This part of work showed that the wireline formation test data can be interpreted the same way as well testing.Secondly,the researchers studied the interpretation method of pressure buildup data of spherical flow and radial flow,determined the automatic history matching method of well testing data based on genetic algorithm,and programmed the wireline formation testing interpretation software which provides the formation permeability for DST testing.Thirdly,the researchers gave out the determination method of the open well time and yield sequence for general DST according to "exploration oversight Manual" of CNOOC and fields tests,and programmed the optimal design software of DST which optimizes the DST design based on the formation parameters.Finally,the researchers interpreted the MDT data of four producers in six layers applying the developed software and then compared the interpretation results of the DST data and core analysis data.The MDT-interpreted permeability has a linear relationship with DST-interpreted permeability,and no clear relationship with the core analysis-interpreted permeability.The error between the steady productivities calculated by DST optimal design applying the permeability interpreted by wireline formation testing data and that applying the actual test data is less than ten percent.What is more,the optimized DST test shortens the testing time which can greatly reduce the cost.