Sequence Stratigraphy And Favorate Reservoir Forecast Of Silurian And Devonian In Tarim Basin

The application of sequence stratigraphy and technology provides a newmethod for oil and gas-bearing basins exploration. It is also an effective andadvanced method to identify and predict sea faces reservoirs.Based on sequence stratigraphy and existing oil and gas exploration experiences,with seismic, drilling, well-logging, core data and other available achievements, thisdissertation is focused on the study of sequence stratigraphy of Silurian-Devonian inTarim Basin, sequence boundary was confirmed, system tracts were divided,sequence stratigraphy framework was established. This paper also discusses thecharacteristic of inner sequence ingredients, summarizes the time-space distributingdisciplines. Moreover, combined with regional structural conditions and fillingcharacters, favorable reservoirs were forecasted.Using the seismic data, drilling, well logging, outcrop and well core, combinedwith the analysis data, the Silurian and Devonian are divided into five seismicsequences and ten logging sequences.The Sq1,Sq4,Sq8,Sq9 and Sq10 are the typeâ… sequence , while the others arethe type â…¡sequence. By comparison with the classical typeâ… sequence , the LST oftypeâ… sequence in this basin are characterized with lack of the deposition systemsuch as basin floor fans and slope transgress complex. In the typeâ…¡sequences, andthe main deposit systems are the coastal faces (tidal flat faces) and shelf facesdeposit. The sequences that formed in the early Silurian are on the uneven erosionsurface, and the main deposition style is that of filling the surface.while during the middle and latter Silurian, the sequences are formed in thebroad and even basin;During upper Silurian-Devonian, the basin is in extrusion state,and turn up large scale uplift;During upper Devonian-lower Carboniferous, turn up anew transgressive overlap, and develop a set of widespread sandstone-Donghesandstone. This kind of sequence framework is different from the classical one thatderived from the passive continental margin, and reflects the sequence characteristicof the depression basin of the stable platform. Sq1, Sq4, Sq10 are three favorableexploratory sequence of the Silurian and Devonian in Tarim basin.