Метод ускорения расчета давления при изменяющихся дебитах по истории эксплуатации скважиныстатьяИсследовательская статья
Статья опубликована в журнале из списка RSCI Web of Science
Статья опубликована в журнале из перечня ВАК
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 8 апреля 2022 г.
Аннотация:Interpretation of well testing on unsteady state is based on the idealized caseof a single well operating at a constant rate. However, in practice, the flow rateis not constant, in particular due to the difficulty of maintaining a constantrate. If do not take into account the changes in the flow rate before the research, this will cause inaccuracies in the calculations and errors in the analysis of the well test results. Traditionally, the transition from modeling the wellproduction process with a constant flow rate to modeling with variable ratesis carried out using the principle of superposition over time. The algorithm forcalculating pressure using the superposition principle has a linear complexity,where the most resource-intensive element is the calculation of the differential pressure function. In addition, the calculation can take considerable timewhen calculating a complex analytical model ‘well – reservoir – boundary’ forcases of well production history with tens and hundreds rates. Such casesmake these calculations unsuitable for engineering practice.The method is proposed to speed up of a bottomhole well flowing pressurecalculation with variable rates according to the production history in thispaper. The proposed method is based on the use of the pressure drop approximation function, which is a fourth-order polynomial of the logarithm oftime. The coefficients of the polynomial are found by using the Levenberg –Marquardt optimization method. The comparative analysis of speed andquality of bottomhole well flowing pressure calculation for three models isgiven by the number of analytical model function calls, the calculation time,the maximum relative deviation, the average quadratic deviation of the relative error. It is shown that the calculated pressure values obtained by the traditional and proposed method (using an approximating polynomial function)for models of a vertical well, a horizontal well and a horizontal well with multistage hydraulic fracturing in an infinite homogeneous reservoir are identical.The proposed method allows to significantly increase the calculation speedwith minimal calculation error.