INTERPRETATION AND EVALUATION WITH DRILLING FOR MESOZOIC IGNEOUS BURIED HILL FRACTURED RESERVOIRS IN THE LIAOXI UPLIFT

The Mesozoic of X structure in the south end of Liaoxi Uplift is a buried hill reservoir consisting of fractured igneous rocks, and the distribution of fractures is extremely uneven. The geological responses of the Mesozoic reservoirs are obviously different from the conventional reservoirs lying above them. The complicated engineering factors adopted during drilling process have great impacts on the quality of logging data, and may bring many difficulties to the integrated data interpretation and the identification and evaluation of reservoir effectiveness. In this paper, after careful quality screening of logging data, indication parameters, that may truly reflect the formation fluid, are selected. Together with the logging engineering parameters, a logging evaluation standard for buried hill reservoir is established for accurate interpretation and evaluation of the reservoir fluid. Comparison with the sampling and testing results suggests that the integrated logging interpretation standard and interpretation method for the structure has been greatly improved. The improvement of coincidence rate of fluid interpretation and reservoir evaluation proves that it is a new approach for fluid interpretation and igneous reservoirs evaluation and could be used in surrounding areas under complicated well conditions. It successfully helped the discovery of the high yield light oil field in X structure and is a breakthrough of oil and gas exploration in the X structure of Liaoxi Uplift as a case with important reference value for future exploration.