Xinjiang Petroleum Geology ›› 2024, Vol. 45 ›› Issue (6): 735-741.doi: 10.7657/XJPG20240613

• APPLICATION OF TECHNOLOGY • Previous Articles     Next Articles

Configuration Pattern of Combined Conventional Mercury Intrusion-Constant Rate Mercury Intrusion Curves and Its Indicative Significance

DAI Jinyou(), LEI Xizhen, PI Sha, SHEN Xiaoshu, CHEN Daixin   

  1. School of Petroleum Engineering, China University of Petroleum, Beijing 102249, China
  • Received:2024-05-11 Revised:2024-06-05 Online:2024-12-01 Published:2024-11-26

Abstract:

Based on the configuration theory and the analytic hierarchy process (AHP), the configuration shapes of the combined conventional mercury intrusion-constant rate mercury intrusion (CMI-CRMI) curves were classified, and a universal three-segment configuration pattern for the curves was established. The indicative significance of this pattern to the pore-throat systems and their wetting hysteresis was clarified. The results show that the combined CMI-CRMI curves consist of three configuration segments: a, b, and c, which are interconnected but exhibit distinct shapes. The segment a displays an overlapping shape, indicative of a macro-pore-throat system, where the combined CMI-CRMI curve shows no wetting hysteresis. The segment b demonstrates a separated shape and can be subdivided into subsegments b1 and b2. Subsegment b1 indicates a meso-pore-throat system, where the CRMI intrusion curve shows no wetting hysteresis, but the CMI curve does. Subsegment b2 also indicates a meso-pore-throat system, where the combined CMI-CRMI curve shows wetting hysteresis. The segment c exhibits an overlapping shape, representing a micro-pore-throat system, where both the CMI and CRMI curves exhibit equal wetting hysteresis. The deformation of the mercury meniscus during CMI is concentrated in the segments b and c, while the deformation of the mercury meniscus during CRMI is concentrated in the segments b2 and c. Subsegment b1 in both the CMI and CRMI curves can be used for contact angle correction. This three-segment configuration pattern of the combined CMI-CRMI curves provides a significant guidance for segmental contact angle correction and pore-throat distribution characterization.

Key words: conventional mercury intrusion, constant rate mercury intrusion, capillary pressure curve, configuration pattern, pore-throat system, wetting hysteresis

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