Sedimentation And Reservoir Forming Features In Shallow-middle Buried Glutinite In Yanjia Area, North Structural Belt Of Dongying Sag

Glutinite in Yanjia area were developed in multiple sedimentation types with complexspacial superposition. Because of small in scale, complex in developing stages, fastvariation in oil/water contact, and uncertainty in trap validity, etc. It is the key point thatslowed down petroleum exploration in this area.The thesis carried out precise sequence stratigraphic classification in Yanjia area, andidentified7fourth-level sequence units in the Third member of Shahejie formation (Es3forshort) with the lower part and the middle part of Es3separately containing3fourth-levelsequence units. In this way, lateral distribution and variation of sand body in different stageswere made clear.There are two sedimentation types in Yanjia area, vertically exhibited as subaqueousfan in the lower and middle part of Es3, and as fan delta in the upper part of Es3.Glutinitedistributed along denudation plane as stripe, Small gully facing with thickness center, themiddle part of subaqueous fan and fan delta front is favorable for development of goodreservoir bed.Through detailed analyze of typical reservoir in multiple blocks in Yanjia area, it isclarified that there are mainly four types of reservoirs namely: anticlinal structural reservoir,fault screened structural-lithologic reservoir, diagenetic differentiated structural-lithologicreservoir, and up dip pinchout reservoir. The effectiveness of the traps is mainly controlledby the following factors: the structural shape, the heterogeneity of the reservoir, the fault ofturning towards the basin, the lithologic allocation and the depth of the reservoir.Study showed that reservoir tend to distributed as ribbons laterally and diversified vertically. Hydrocarbon tended to be more viscous upward. Therefore, reservoir formingmodel of “differential ordered reservoir bed and fluid” was established. Finally, aimed atdifferent types of reservoir in different structural belts, exploration concept and evaluationmethod were put forward.Topic of the thesis is closely related to practice, and achievements obtained were fedback to exploration in good time. By way of well location deployment, new productioncapacity was established and proved oil in place was declared and good exploration andproduction benefit was obtained.