The key technology and application research of lithology reservoir——An example from FU 11 well area in eastern Junggar basin

With the continuous improvement in exploration in hinterland and east of Junggar basin,it is more difficult to find the phenotype structure trap.In the situation of exploration targets having become more complicated,the oil and gas exploration transform from the structural reservoir exploration to the lithologic reservoir exploration,for the previous exploration targets based on fault block in the ancient uplift and low-amplitude anticline are becoming ever less,it is an inevitable trend of exploration targets turning to lithologic reservoirs on the slope and deep depression.The characteristics of this kind of oil and gas reservoirs are low amplitude of traps,small thickness of sand layer,rapid change in horizontal and difficult to distinguish and evaluate for seismic data.However,for the geological difficulties,we taking the lithologic reservoir of well Fu11 block in eastern Junggar Basin for the research object,combining geological,seismic and logging to analyse the lithologic reservoir characteristics of well Fu11 area,study the exploration theories,methods and the effectiveness for lithologic reservoir of this area.Then,we select many kinds of targeted geophysical technology and develop a series of technologies to identify and evaluate the clastic rock lithologic traps for Junggar basin,which include the technology of proper calibration by well and sesimic data,automatic tracking with full 3-D,fracture automatic detection,analysis of dynamic evolution of structure,analysis of sedimentary microfacies,reservoir prediction,and detection of fluid and evaluation the favorable goal.Finally,applying these technologies to predict lithologic traps of Sangonghe formation(J1s) in FU11 well area in eastern Junggar basin,eventually we found three traps of lithologic and fault-lithologic which can be drilled.The sedimentary microfacie of these traps is the sand of mat shape in front of delta,trap area between 1.75 km2 and 6.1 km2,and the thickness of sand is about 25m to 35m.It is the most important that these traps are all located in the favorable positions by hydrocarbon detection.The total areas of these traps is 12.39 km2.And then,we evaluate and select a number of wells in these favorable lithologic traps.As it has been proved that these technologies is effective and practical by real drilling,it improves the quantity and precision of lithologic traps identification and provides a powerful technical support for lithologic reservoir exploration and development.