Известия Томского политехнического университета: Инжиниринг георесурсов (Feb 2020)
DIAGNOSTIC CRITERIA FOR IDENTIFICATION OF FILTRATION FLOWS DURING HORIZONTAL WELL TESTS
Abstract
The relevance of the research is caused by the need to identify the filtration flow regimes for operational determination of hydrodynamic parameters of oil reservoirs during horizontal well tests by bottomhole pressure buildup curves The main aim of the research is to develop diagnostic criteria of deterministic pressure moments for identification of filtration flow regimes during horizontal well tests in oil fields by pressure recovery curve. The methods are based on theory and practice of non-stationary horizontal well tests, linear algebra, system identification, system analysis. The proposed diagnostic criteria were tested on the basis of field data of horizontal well tests in oil field by bottomhole pressure buildup curve. The results. The authors have developed the diagnostic criteria for identification of early-radial, linear and late-radial (pseudoradial) flow regimes on pressure buildup curve during horizontal well tests in the oil fields. The diagnostic criteria are based on the estimates of deterministic pressure moments obtained during horizontal well tests. To define the unknown values of reservoir and bottomhole pressures the adaptive identification algorithms and phenomenological forecasting models of bottomhole pressure with variable parameters were used taking into account additional a priori information about reservoir pressure. The processing of test results of two horizontal wells in an oil field was carried out, it is shown that the proposed diagnostic criteria are not inferior in accuracy to the graph-analytical method for identifying filtration regimes and allow determining the time of the beginning and completion of the filtration flows, as well as the time of well shut-in during the tests without the participation of a qualified interpreter.
Keywords
