Identification of low and medium intensity gas leakage location in medium and ultra-high pressure gas pipelines

An efficient method for calculating the location of stationary gas leakage in wells and gas pipelines with medium and ultra-high pressures is presented. An algorithm for constructing the dependence of the compressibility factor of the gas mixture with a predominance of methane in the region of ultra-high pressures based on experimental data of pressure and temperature is proposed. The algorithm for calculating the leakage location is based on the Bellman method of quasi-linearization of nonlinear problems, with an additional hypothesis of the linear dependence of pressure and temperature on the leakage location coordinates used at each iteration. The issue of selecting the initial approximation is considered, and the advantage of calculating the initial approximation using a simplified non-isothermal flow model is justified. Examples of solving practical problems of high interest are given, and the high accuracy of calculating the gas leakage location using the proposed algorithm in gas pipelines with medium pressures (around 9 MPa) and ultra-high pressures (around 20 MPa) for small and medium gas leaks is demonstrated.