167 / 2019-06-11 18:56:42

Application of Seismic Sedimentology in Cretaceous in Northern Songliao Basin, China

Songliao Basin, Seismic Sedimentology; Stratal Slicing; Attribute Analysis, Denglouku Formation

Songliao Basin is a large continental sedimentary basin. In order to accurately identify the plane distribution of sedimentary system in northern Songliao Basin. Seismic sedimentology techniques are discussed in different projects in the Northern Songliao Basin, such as phase transformation technique, stratigraphic slices and points frequency interpretation, point tracking, semblance attribute analysis, instantaneous amplitude, 3D visualization technology. The No.1 Section of Nenjiang Formation is taken for example to analyze applications of the seismic sedimentology. on the basis of fine interpretations. And a series of strata slices are made in different three dimensional seismic projects, These slices provide continuous depositional seismic images of the Nenjiang Formation. From these slices, distribution ranges of delta and lakes depositional systems in different periods are described, and also distribution ranges of distributary channels and distributary interchannel are elaborated. Through this research, we have analyzed its space-time evolution characteristics, deepened the Nenjiang Formation Reservoir distribution law after studying the distribution of sedimentary facies, and have analyzed its spatial evolution features. From k2n1sq1 to k2n1sq2, the base level is increasing, and depositional ranges of delta is reducing.As a result, lake facies area is gradually enlargeing.During k2n1sq1 period,sublacustrine fans are developed partly in the lake facies, dominated by siltstones and muddy siltstones, with the range of depositional depth from 0.5m to 5m.High resistance curve values are shown between a big section of mudstones in well logging curve with the shape of a finger or a funnel. and the highlight reflection are shown with the low frequency. During k2n1sq2 period, lake facies area is enlargeing further.Large-scale turbidite channels and fans are developed in the delta front coming from northern basin and deep lake area. Using 3D seismic materials with area of 13000km2 distributed in the Central Depression in the northern Songliao Basin, sedimentary characteristics is elaborated. turbidite channels and fans are widely found in Daqing anticlines, Sanzhao sag, and northern Gulong sag. Totally 26 large-scale channels and 16 sublacustrine fans are deposited and developed. Large-scale turbidite channels and its end sublacustrine fans stretch to the south distributed in the Daqing anticlines and to its both sides, with the distance from 100km to 50km.Through analyzing the space-time evolution characteristics, Nenjiang Formation reservoirs distribution is cognized.Seimic sedimentology techniques are well applied in the Nenjiang Farmation, and good results have been acquired.From this study of Nenjiang Formation, this technology could be used further in Denglouku Formation and others,and so it has a positive significance to identify fan delta in lakes of Denglouku and Shahezi Formation.