Study On Subtle Hydrocarbon Reservoirs Of Yingchen Formation In The Northern Slope Zone, Lishu Faulted Depression

The northern slope zone with a higher degree of exploration and development is one of the tectonic units in Lishu faulted depression which is located in the southeast uplift of Songliao basin. The focus of exploration is looking for subtle reservoir, But there are some barriers in the hydrocarbon exploration, such as reservoir characteristics, trap types and hydrocarbon accumulation. My paper is born of destiny.Combining with relevant literature data, under the guidance of the theory of sequence stratigraphy, using seismic attributes analysis as a technical means, the following main results were obtained knowledge.The reservoir of the study area could be divided into three levels. The thickess of the first grade reservoir are more than3meters, and most of the reservoirs are in subaqueous channel sand or mouth bar bodies. Single sand thickness in the2-5meters of reservoir has a better oil-gas show. RMS amplitude and relative wave impedance of seismic attributes can better reflect the distribution and changes of the northern slope depositional systems. Under the frame of the sedimentary facies, sand distribution and seismic attribute analysis, the study area could be identified three classes,10subclasses subtle traps. Most of them are lithologic deposit (including updip wedge—out deposit, lenticular hydrocarbon pool), unconformity deposit (stratigraphic overlapped deposit), and fault-lithology trap.The characteristies of the oil-gas shows is gas in west and south, but oil in east and north. The lower part of Yingchen formation contains gas, but the upper mix with oil and gas. The factors of contrilling oil accumulation are sedimentary microfacies plays a decisive role in reservior quality, vertical communication of fault is the key factor to stratigraphic traps accumulation with adjustment. Sedimentary, structure and evolution of the slope jointly decide the types, distribution and size of the traps.Consolidated sedimentary facies, reservoir evaluation, trap distributing prediction that the most favorable reservior type is updip wedge—out deposit in subaqueous channel, followed is fault-lithology traps, lenticular hydrocarbon pool is the last. Three of these areas are the most favorable, respectively SW33x region to the southern, SW31-L3region and SW202region in the west side of Bawu fault.