The Theory Research Of Technology Of Detecting Leakage

Oil and Gas pipeline has become a main transport channel of oil and gas. As a result of all sorts of reasons, the pipeline leakage accident sometimes occurs. In order to guarantee the pipeline safe operation, reduces economic loss which pipeline leakage creates, as well as serious pollution which creates to the environment, research on identification of important parameter, leak position andintensity. Specially, determining leakage position is a major topic in the engineering and theory. Also, is an actual problem that needs to solve.Research on the leakage detection technology and method has several dozens years history. The former detection method can be divided into two kinds, one kind is a direct method; another kind is an indirect method. The commonly used direct method has the direct observation method, in the leak detection electric cable method, the pipeline inside surveys method, the optical cable detection method and so on. The indirect detection method is called as water power parameter detection method. It includes pressure surge wave method, transient state model method, quality balancing method and pressure point analytic method. Each method respectively has its merits and demerits, and its application scope. Says in view of the long distance pipeline, at present, there is no method which has been feasible and reliable, also simple, and be used universally. So, this need to make further study the pipeline leakage theory. This is precisely a goal which this dissertation studies.this dissertation in [142] in foundation, this dissertation have finished a theory study of pipeline leakage model (non-pressure testing stage).A nonlinear partial differential equation group was set up to describe the operation of pipeline based on continuity equation, motion equation, and state equation, which was reduced to a linear parabolic type equation with Cardiff linear method. According to the characteristics of operation stage of pipeline, a linear partial differential equation model was developed for the first time, to describe one point leakage (including position,intensity of leakage) in the pipeline during non-pressure-testing stage, the analytic solution was deduced by Laplace integral transform. next basis pipeline operation stage operation characteristic, several additional conditions were given for determining leakage position and intensity, in this foundation, the theorem, existence and uniqueness of the position and intensity function of pipeline leakeges, was proved with the related properties of contraction mapping principle and Laplace integral transform.this is a theoretical foundation for recognizing leakage position parameter and leakage intensity parameter when a pipeline leakagiche, which have provided the technical guarantee for inverse numerical calculation. At the same time, a new mathematical model, which describe single-point leakage in pipeline when operating, has been given, and have proven equivalenc between the two kind models. And, from the new mathematical model, have promoted several essential conditions which the fluid leak occurs in a pipeline.this provide simple condition for further study pipeline leakage question.At last, according to the leakage position expression and leakage intensity expression, a numerical calculation format and two conditions, which are inverse calculation leakage position and leakage intensity, has been structured.