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Sealing Features of Fluid‐Rock System and its Control on Acidic Dissolution in Cretaceous Sandstone Reservoirs, Kuqa Subbasin
Author(s) -
Denglin HAN,
Man LI,
Zhong LI,
TORABI Anita
Publication year - 2015
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/1755-6724.12529
Subject(s) - geology , dissolution , diagenesis , cretaceous , sedimentary rock , pressure solution , porosity , geochemistry , mineralogy , geotechnical engineering , chemistry , paleontology
The Cretaceous Bashijiqike Formation is the main gas‐bearing strata in the northern structural deformation zone of Kuqa subbasin. The acidic dissolution of this formation arose at 5–4Ma, which corresponds to the late burial stage of the Bashijiqike Formation. Variability of interlayer due to rock composition is negligible. Differentiation of acidic dissolution in sandstones was controlled by difference in amount of exogenous acid fluid from underlying strata. For the absence of sedimentary and structural carrier system between the isolated sandstone reservoirs, most fluid‐rock systems show relative sealing feature during later burial stage by sealing feature of formation pressure, geochemical characteristics of formation water and content of diagenetic products in sandstones. Variation of sealing effects for different fluid‐rock systems is obvious. The pressure coefficient is inversely proportional to acidic dissolved porosity of sandstone reservoirs, indicating that the variation of sealing effects for fluid‐rock system mainly controls the differentiation of acidic dissolution.