Application Of TDS Method In Well Test Theory

Pressure semi-logarithmic curve analysis method and type-curve matching analysis method are two mainly commonly used ways in well-testing analysis, yet quite maturely appliable in obtaining reservoir and formation fluid parameters.Though type-curve matching analysis method is now widely used in all kinds of commercial well test software and the applying of it continuously enhanced with the development of modern computer technology and functions, reaching a peak state.It would fail to present reasonable explanations to some actual measured data when it comes to complicated data from oil and gas fields that have more complicated reservoir conditions and well structures, and eventually makes the data useless and causes enormous human and financial waste.For example:(1) As for the low permeability reservoir, the distance the pressure wave transmits during testing time would shorten due to low reservoir permeability, and it would end in the missing of late-time radial flow regime on the testing curve.(2) the early wellbore storage flow regime on the testing curve would be missing due to the asynchronism of the shutting-in time and start time of logging of the pressure well. These are data that coventional well test analysis method can not explain.In this paper, on the basis of full investigation of domestic and overseas methods of interpreting data in these particular circumstances, by comprehensively using methods of modern penetration mechanics, well-testing analysis, reservoir engineering and mathematical physics, etc, the author has detailedly studied and analyzed the TDS technology, and also carried out a detailedanalysis of the TDS well-testing method of a vertical well through the center of the reservoir with infinitely large external border, a fractured well with infinitely large external border and uniform flow rate and infinite conductivity cracks, a fractured well with finite conductivity cracks, and a horizontal well.By building their respective physical seepage flow model, deviating andanalyzing the characteristic pointsandthe characteristic equations of each seepage flow stage, In this paper it finally obtains the analytical methods and the interpretation process by using the TDS technology to explain the measured data with some flow regime missing. Also it gives case studies of some curve types which frequently occur in field measured data, In turn enlightens us on researching the TDS technology.This paper not only does enhance well-testing interpretation methods but also helps to attract people to attach importance on TDS method and use it in practice within domestic areas. More importantly, it provides us with a method to obtain reasonable interpretation of the field measured data, which could hardly be explained by the traditional methods. Therefore, this paper has theoretical and practical significance.