The Volcanic Rocks And The Related Potential Analysis In Shanghe 58 Block Of Huimin Depression

The No. 1 member of Shahejie Fm(Es1) in58 Shanghe block of Huimin sag, Shandong was developed in a shallow lake facies sedimentary basin with several inter-layers of erupted volcanic rocks. Oil and gas distribution regularity of volcanic rocks has attracted highly attention in energy geology field. Lithology and occurrences of the volcanic rocks varied quickly, which made different ideas to reservoir capability of the volcanic rocks. The paper worked on this intensively inhomogeneous volcanic reservoir to clearly understand its lithology, and internal structure and oil and gas enrichment regularity.As the understanding, the volcanic rock reservoirs in Es1 of 58 Shanghe block of Huimin sag are highly density, low permeability and low pore connectivity with low yield of oil and gas. Based on 3 drill core observation and 32 sample measurement, the author has identified that the lithology is mainly the volcanic breccia, breccia-containing tuff and bioclastic limestone. The mineral compositions and the relationships between the various minerals and rocks have also been recognized in volcanic rock and biological limestone rocks. In combination with drilling mud logging data analysis, we set up four volcanic facies and divide three phases of the eruption and subdivide the different rhythm layers of volcanic rocks based on breccia grain sizes.With the help of microscopic CT technology, the paper has scanned some typical volcanic rocks and bioclastic limestone samples to set up3 D modal in individual sample for the fracture, holes and hollow throats variation. Then the porosity and permeability of lithoreservoirs have been estimated and the fracture characterization of volcanic reservoir and the advantageous parts of pore connectivity have been clear by comparing the volcanic rocks and biological limestone in each different period. Integrated all the information, the paperh as predicted the targets for exploration of oil and gas in volcanic reservoir, which provided mineralogical evidences and lie a sound basis for volcanic reservoir development in the future.