STUDY ON SANDSTONE DISTRIBUTION AND SEDIMENTARY CHARACTERISTICS OFTHE FOURTH MEMBER OF SHAHEJIE FORMATION IN DAMINTUN SAG, CHINA

摘要

B ased on geological exploration results and geophysical logging results, this paper studies the sandstone distribution and sedim entary system characteristics o f the Shahejie Form ation o f the D am intun sag oil and gas reservoir, and obtains the follow ing conclusions: the fourth section o f the Shahejie Form ation (Es4) in the study area The sand body o f the system dom ain is very developed, w ith the characteristics o f large sand body thickness and high sand content o f sand body, and its distribution has a good regularity in space. The sand body thickness o f the low -level system dom ain in the study area is 620 m eter, the m inim um value is 0m, and the average value is 64.15 m eter. T he sand body o f the Es4 lake expansion system in the fourth section o f the Shahejie Form ation in the study area is poorly developed. G enerally, the conglom erate o f the Shahejie Form ation in the study area is distributed from the northw est to the southeast. The m axim um thickness o f conglom erate is 247.5 m eter, the m inim um value is 0m , and the average value is 8.45 m eter. The high value area o f conglom erate thickness is m ainly located in the northw estern part o f the study area, and its thickness is generally greater than 60 m eter. T he sedim entary system types o f the fourth m em ber o f the Shahejie Form ation in the D am intun depression can be divided into three sedim entary system s: fan delta, lake and turbidite. B ased on the Sk-a, K g-a and C M plots o f the particle size param eters o f the sam ple, the partial deviation o f the E s4 reservoir is m ainly positively biased, reflecting that the sedim ent is w eakly m odified by the w ave; the sandstone o f the D am ingjie Form ation o f D am intun is poorly sorted.