Velocity Study And Structure Interpretation In Middle Asia Area Of Kazakhstan

Middle Asia block of Kazakhstan is a risky exploitation field of SINOPEC. There are no 3D survey grid and less drilling wells. The prospecting wells are mostly aimed at shallow layers. The degree of exploration of this area is very low. In order to find out advantageous prospecting target,the research of Areal structure analysis, reservoir type analysis, velocity analysis, integration interpretation, structure graphing have be developed in this area.During the characteristic analysis of layer, structure and evolution in Area structure, this paper adopts the area analogy method and mainly uses the data in Kashagan and Tengiz oil field for reference, which also located on Pre-Caspian Basin Asterahan-Akjiubin uplift belt. On velocity analysis, it mainly adopts stack velocity spectrum after process to fit average velocity curve and average velocity field, and uses the forward modelling technique to ascertain the precision of the velocity field and to settle the basement for ascertaining the structure. Then, by means of integration interpretation and varying velocity graphing, it draws the tectonic figures and evaluates advantageous targets. At last, this paper analyses and sums up the condition of gas and oil accumulation and main control element in this area by referring to tectonic figure, well drilling situation and seismic data of peripheral oil field.In the research, we mainly aim at the Pre-Caspian Basin salt horizon development, salt dome upper bending and layers puncturing phenomena and special velocity of salt horizon. In view of velocity trap of time section formed by heavy layer litho herm, we analyze the two forward modeling methods: Structural Model and Stratigraphic Model, then compares their effect. Thereby velocity field is confirmed and structure of the area is ascertained to figure out. The study of whole project settles the basement for the exploration of this work area, and good effects are shown by using forward modeling technique during the real prospecting applications.