Igneous rock reservoirs of the Well Shang 741 area in Huimin Sag

There are 3 sets of igneous rocks in the area of Well Shang 741 in the Huimin Sag. The first set consists of volcaniclastic rock and basalt, and is distributed in the first member of Shahejie Formation (Es 1 ). The volcaniclastic rock and basalt are distributed in coniform and stratiform occurrences, respectively. The second and third sets of igneous rocks are stratiform diabase, which developed at the later Es 3 , and invaded into the middle Es 3 member. By integrated analyses and comparisons of exploitation well with the three dimensional seismic data, the distribution area, shape and occurrence of the igneous rocks of various periods in Well Shang 741 area are determined. The igneous rocks of Well Shang 741 area can be classified into volcanic vent filled facies, outbreak facies, overfall facies, and invasion facies, etc. The outbreak and invasion facies are further divided into sub facies. The development features of reservoir space are different in different lithofacies belts. In a word, around volcanic vent is favorable reservoir development position.