Exploration Techniques And Application In Marine Carbonate Reservoir

Controls of sedimentary lithofacies,karstification,tectonic disruption factors in Upper Ordovician reef-bank complex of Tazhong NO.1 slope break and Lower Ordovician Yingshan formation weathering crust.It is developed reef-bank complex of Upper Ordovician Lianglitage formation along Tazhong NO.1 slope break, in which centralized at Liang 2 segment and it moved from inner belt to outer belt.The most developed reef-bank is Tazhong 62 well zone.The double control of palaeogeomorphology and tectonic disruption,it is mostly vertical vadose and lateral underflow zone which the thickness of crust is total account to 100-280m.It has characteristic of zonation with the most developed zone at crust slope zone.By means of geology-seismic comprehensive workbench according to different main factors,it can not only recognize three seismic response:moniliform strong amplitude,chaotic reflection and weak reflection,but also make it clear reservoir geology-seismic model applying wave equation forwarding equation;It is also applied the technology of palaeogeomorphology recovery, waveform analysis,well-seismic joint inversion, frequency spectrum to predict karst landform,favourable facies belt,the distribution characteristic of karst By means of coherence enhancement, dependent variable analysis, numerical simulation, prestack nonisotropy analysis to predict genesis fracture and distribution of fracture.It is performed the technology of seismic petrophysical parameter analysis, elastic impedance inversion,AVO attribute analysis to study prestack reservoir The result is shown that the favorable area of reef-bank body are 659km~2 in Tazhong NO.1 slope break of Upper Ordovicion reef-bank complex. The quantity of resources are 2770×108m~3.The favorable area of crust are 1866km~2, The quantity of resources are 7580×108m~3 in weathering crust karst reservoir of Lower Ordovician in Tazhong Area.From 2004 to 2008,it is submitted 83 wells location applying geology-seismic comprehensive prediction technology to help the oilfeiled.In it 33 wellls are accepted,one of 13 wells are gained high production stream ,especially Tz82 ,in which it becomes the first thousand ton wells.After then it is born a hundred million tons Ordovician organic reef oilfield.Turning over to the higher authorities three-levels reservoirs are 3.0×10~8m~3t.The reservoir and drillings coincidence rate is over 90% which proved its effective.So it buit up the technology system of geology-seismic comprehensive prediction,and the same time, it guided the similar area for carbonate rock reservoir prediction and evaluation.