The Prediction Of Reservoirs For The Second Segment Of Xujiahe Formation Gas Pool Of Hui Long Area In West Sichuan Depression

Western Sichuan Depression Dongpo Huilong region the Chuanjiang566wellsbeing drilled back to Long1well required to the Xujiahe Sec obtain betterbreakthrough, showing the area of huge areas of deep exploration and developmentpotential, and opened the back to Long deep exploration of the prelude. WesternSichuan Xujiahe group2reservoir is a super-dense, fractured gas reservoir, thereservoir of "two superpowers"-ultra-compact, ultra-low porosity and permeabilityand extremely non-homogeneous characteristics, coupled with the region of thedrilling, pre-mainly two-dimensional seismic data, so the effective reservoir with theforecast there are many difficulties and problems, mesh crack developmentcharacteristics such as high-energy sedimentary microfacies control quality sand bodydistribution law in the oil and gas exploration are worthy known as a worldwideproblem, mainly due to the reservoir buried deep, ultra-compact, high-frequencyattenuation of seismic signals effectively narrow band of reservoir seismic reflection,the frequency is very low, the seismic response characteristics is not obvious. Thuscarried out in the area Xujiahe group2reservoir difficult, highlight its advanced andinnovative.Xujiahe Sec for Dongpo back to Long Triassic low porosity and lowpermeability sandstone gas reservoirs in the collection, research, previous resultsbased on natural gas geology and tectonics theory, to study its structure characteristics,analysis of the tectonic evolution, fault, crack development characteristics anddistribution law; high-resolution sequence stratigraphy theory for the fine division ofthe guidance on the target layer deposition cycle, the establishment of the target layerdeposition mode; the use of the sedimentology, reservoir geology, seismicstratigraphy, well logging geology and modern geophysical techniques such as the target layer of sedimentary microfacies, crack distribution, reservoir properties, suchas systems analysis and prediction; understanding of an integrated geological andgeophysical discriminant technology and methods are combined to achieve afavorable reservoir prediction. And finalize the east slope of the regional structuralinterpretation mode and the formation of deep fault; confirmed the direction ofWestern Sichuan Depression Dongpo the Huilong region Xujiahe group Secsedimentary facies with transitive source, the initial grasp of the reservoir conditionsand oil and gas rich set of relationships; Prediction of effective reservoir. Throughresearch confirmed Dongpo back to Long:1) simple structure, a south eastoverturning nose structure, tectonic movement of the area has obvious and inheritance,but the tectonic stress is relatively weak, Babel large fault only River region in thework area west little development, and other regional fault less.2) back to LongXujiahe deposition studies confirm the area Xujiahe group Sec provenance from thework area south east, is a delta front of the overlay, the main microfacies underwaterdistributary channel interdistributary bay, local mouth bar deposition.3) back to theasparagus home river, Sec effective reservoir is mainly distributed in the main part ofnose structure, fracture porosity, multi-phase shunt river stacked sand bodies, theseismic response for the "strong phase interrupted, weak low-frequency amplitude ".4)Huilong small faults within the home river, Sec layer is developed, and widelydistributed, fault mesh cracks, favorable reservoir properties transformation.Prediction of favorable reservoir revealed that back in the river area and work areasoutheast of the work area northwest of Long area, past and present higher structuralposition, a small fault development in the transformation of the reservoir layer, thecracks developed area of energy-deposition of micro-phase network stack together,the reservoir containing gas is the most favorable quality reservoir with a developedarea.