The Structure Characteristics Research And Accurate Interpretation Of Pu 1 Reservoir In Block Gu-59 Of Gulong Oilfield

Putaohua Reservoir is the main production layer of Songliao Basin, lying on Yao-1 member. The main part of Gulong oilfield is located in a syncline with north-south trend between Taikang uplift and Daqing placanticline, stretching cross Qijia-Gulong depression and Hupao-Daan terrace. The overall trend of structure is sag in middle and culmination in two sides. The block Gu-59 is located in the south-eastern of Gulong Oilfield. The accurate research of Putaohua reservoir structure characteristics in block Gu-59 of Gulong reservoir is not only helpful to petroleum exploration and development in the zone of interest, but also have a profound significance for exploration and development in South of Daqing Placanticline.The study on the basis of raw data analysis, in view of focal and difficult points of processing, such as the static correction, improving resolution, protect the effective signal, eliminate distinctions of the vertical and horizontal energy and migration imaging, we use combined static correction with constraint surface model, fractional domain image denoising, surface consistent amplitude compensation, source-receiver domain two-step surface consistent deconvolution and prestack time migration technology, obtaining good results. The new processing product shows a stronger purpose layer reflection energy, high SNR, obvious wave group characteristics, abundant information of layers, clear characteristics of tectonic, breakpoints and fracture section.Through summarizing the previous research and utilizing the data of geology,3D seismic, drilling, logging, cores et al, this paper takes the theory of structural geology, sedimentology and petroleum geology to study this subject. The first, calibrate Pu 1 reservoir by selecting 56 wells and synthetic seismic. Afterwards, confirm seismic reflection characteristics of horizons in work area by the calibration. Setting up the accurate structure framework is depend on stratigraphy correlation, the characteristics of seismic section and seismic reflection. Based on this, we have taken standard section to trace, compare and explain the each target stratum and fracture. The time-depth conversion is adopted the varying-velocity mapping approach of fixing v0 and variable β to compute the velocity field in 3D space, so that drawing the reservoir structure map. The final, we have drawn isopach map of each sand layers on the basis of sand layers top-bottom boundary structure map of Putaohua Reservoir.Based on detailed study on structure in the study area, we have identified 7 entrapments, summing to 25.29 km2. There are four types of entrapments:fault-block, fault-anticline, fault-nose and anticline. The fault-block and fault-nose are the main entrapments in our work area. There are 63 faults explained in work area, whose character is normal fault with NWW and NNW trend. The length of fault with NNW trend extend longer, and the NWW trend one extend shorter. The fault had mainly developed in Nenjiang formation to Qingshankou formation in vertical, and the main structure types are graben and horst. The fault with NWW trend cut off the fault with NNW trend in the plane, which shows the fault with NWW trend developed earlier.