Research on the Method for Determining the Lower Limit of Physical Properties of Thick Sandstone and Gravel Oil Layers

The determination of the lower limit of oil reservoir physical properties is crucial for accurate identification of oil reservoirs. For a thick sand and gravel reservoir with an average thickness of 25.4 m, the conventional methods of determining oil content and testing data to determine the lower limit of porosity are no longer sufficient to meet reserves and production needs. Therefore, this article integrates various data and clarifies the logging response characteristics of thick sandstone reservoirs, and applies core calibration logging. On the basis of conventional methods for identifying the lower limit of physical properties, the core nuclear magnetic resonance analysis method, nuclear magnetic resonance logging comprehensive calculation analysis method, and mercury intrusion saturation analysis method were used to comprehensively determine the lower limit of physical properties of thick oil layers. Accurately ensuring the classification identification and reserve submission of thick sandstone and gravel oil layers, while avoiding interlayer interference caused by the simultaneous production of oil layers with different porosity levels, as well as the production of inefficient oil layers, provides necessary technical support for the rapid construction and cost reduction of oil fields.