Advanced Materials Research Vols. 734-737

Abstract: The rapid lateral variation of fluvial sand-bodies seriously affect the development of oil and gas field. One long-term base-level cycle (LSC), four middle-term base-level cycles (MSC) and nine short-term base level cycles (SSC) are recognized by researching the stacking patterns and volumetric partitioning according to the core, well log and seismic data in He8 member of A gas field, Ordos basin. The base level cycles which are mainly base level rise half cycles are mainly composed of braided and meandering river deposits. The evolution of depositional system has experienced three stages: braided river deposition in the earlier stage, braided and meandering river transition coexistence in the middle stage and only meandering river deposition in later period. The braided channel sand, mid-channel bar and point bar are mainly reservoirs which show belt and ribbon along the SEE trending. These sand-bodies are vertically and laterally stacked with good continuity in the early MSC1, MSC2 and MSC3, while isolated and with poor continutiy in the early MSC4. The sedimentary microfacies and diagenesis affect the fluvial reservoir quality including lateral continuity, porosity and permeability and the buried depth of the good reservoirs with development of secondary solution pores is less than 3500m in this area.

Abstract: Sequence is a relatively conformable succession of genetically related strata bounded by unconformities or their correlative conformities. The correct identification of sequence boundaries is the key to the success of the sequence stratigraphic approach. Stratigraphic boundaries provide the fundamental framework for the genetic interpretation of any sedimentary succession, irrespective of how one may choose to name the packages of strata between them. Sequence stratigraphy of main research content is mainly chronohorizon (unconformity or conformity) identification, and to determine its causes and characteristics. Then, the key to sequence stratigraphy is identification unconformity and their correlative conformities. Unconformity and their correlative conformities on the seismic profiles, well logs, lithology, paleontology, and geochemical data have distinctive sequence boundaries mark characteristics.

Abstract: Three-dimensional(3-D) seismic data and structure analysis of the Lishu subasin in Songliao basin indicates that Qinjiatun fault zone is composed of two faults: East-Qin and West-Qin fault. This fault system initially formed at Huoshiling stage, peaked at Shahezi stage and faded dramatically from Yingcheng stage. The Qinjiatun fault was important in controlling strata thickness and distribution of the Huoshiling formation. Qindong fault, a typical strike-slip fault, developed relatively later, cutting the Qinjiatun fault, The major active stage was in Denglouku-Quantou stage, and weakened in the end of late Cretaceous. Qinjiatun fault zone was reversed at Denglouku stage when the regional stress went compressive, generating a structure nose that was potentially beneficial for hydrocarbon to accumulate. The strike-slip Qindong fault became active relatively later, cutting through the previous strata and proving pathways for both accumulation and effusion of hydrocarbon.

Abstract: Multifunctional electromagnetic prospecting technology, include the time domain induced polarization (TDIP), the artificial source phase induced polarization(RPIP), the natural field audio magnetotelluric sounding(AMT), Controlled source audio magnetotelluric sounding(CSAMT),etc. They form a kind of multi-parameter electromagnetic prospecting technology from shallow to deep. The method have characteristics such as high-resolution, diversified-means, bigger-detection-depth etc, can obtain the electrical parameters of apparent resistivity, apparent polarization, phase, so it can reflect the electrical characteristics of the geological structure and rock & ore to provide information for deep or concealed mine. This overview just summarized achievements made in methods and techniques, basic principles, technical characteristics, applications cope and conditions, case study and results, in hope of giving some guidance for metallic ore exploration.

Abstract: By the aid of such core analysis data as lithochemical data, physical property data, thin sections and capillary pressure curves, studies were made on the physical properties and its primary controlling factors of carboniferous carbonate reservoirs of Zhanazhol oilfield. The studies were focused on such aspects as lithology, void type, pore connectivity, developing degree of vugs and fractures and fracture type. The study shows that the reservoirs of KT-I are principally multiple void-typed with middle porosity and permeability, with lithology, developing degree of vugs and fractures and fracture type being the primary controlling factors to their physical properties, and that the reservoirs of KT-II are principally fracture-pore typed with low to middle porosity and permeability, with lithology, void type, pore connectivity and fracture type being the primary controlling factors.

Abstract: Shuguang lower hill is buried 3500 metres below the band, the exploration difficulty is big and high quality recognition is difficult. According to its complex lithology characteristics, poor porosity and strong heterogeneity, with the application of comprehensive conventional coring, thin-section analysis, scanning electron microscopy and conventional curve data for analysis of reservoir characteristics of the lower hill, lithology and reservoir criterion are established, more over the fracture strata section of the hill is identified. The reservoirs are mainly composed of carbonate rocks and quartzite, the accurate lithology identification provides geological basis for the next step of well deployment.

Abstract: Through the studying of heavy mineral assemblages and ZTR index variation features, this paper analyses the provenances and sedimentary systems of Saertu reservoir in Cretaceous of Jiangqiao-Pingyang area, western slope zone in northern of Songliao basin. It is concluded that there are three major sedimentary systems in the Saertu reservoir depositional period, named the Nehe-Yian sedimentary system in Northeast, Yingtai sedimentary system in Southwest, Qiqihaer sedimentary system in Northwest. The intensity and influence scope of the sedimentary systems in sedimentary period of SaII+III, SaIand Sa 0 reservoir changed. During the sedimentary period of SaII+III reservoir, research area is mainly controlled by the Qiqihaer and Yingtai sedimentary systems, the control action of Nehe-Yian sedimentary system in the research area is faint. During the sedimentary period of SaIreservoir, Nehe-Yian sedimentary system control the sedimentation of mainly region in research area, the control range of Qiqihaer sedimentary system has shrunk to the West of Jiangqiao area, the Yingtai sedimentary system dropped out of the research area. During the sedimentary period of Sa 0 reservoir, the control action of each sedimentary system basically inherited the distribution pattern of the sedimentary period of SaIreservoir, but the source supply capacity weakened further.

Abstract: The time and space evolution of sequence architecture and depositional systems has attracted much attention in the geological field. Meanwhile, due to the recent excellence, the Oligocene lacustrine rift basin takes a key position during geological research in Huanghekou depression of Bohai Bay Basin in east China. However, the systematic researches of the depositional sequence of Dongying formation in Huanghekou depression appear little, thus this study aims that using many seismic lines, complemented by well logs and cores to thoroughly analyze the time and space allocation of depositional sequence of Huanghekou depression and its major controlling factor, base-level change, in a typical rift lacustrine basin. The Oligocene Dongying formation in this article will be divided into three composite sequences on the basis of unconformities on basin margins and correlative conformities in the basin center. Every sequence is composed of a regional depositional cycle from transgression with an onlapping lacustrine expanding systems tract (EST) to regression with a prograding highstand systems tract (HST). And five sequences can be further identified by subordinate discontinuous boundaries in Huanghekou depression. The evolution of depositional systems is associated with base-level change within sequences. In Lower and Middle Dongying formation (ESTSQ3, HSTSQ3, ESTSQ2), depositional systems are dominated by braid river delta and sandy beach-bars. During the late period of Dongying formation (HSTSQ2, SQ1), depositional systems are characterized by meandering river delta or braid river delta deposits. And base-level change is one of major controlling factors, of which the shape and scale control the development of the depositional sequences. Base-level changes, via affecting the A/S, directly control the depositional states and determine the unique depositional sequences structure: in the northern steep slope, multiple meandering river deltas systems exist. In the middle of the depression, the large areas of beach bars can be found. And the depositional system is continuously developed with the large-scale braided river delta in the southern gentle slope.

Abstract: To identify and segment automatically the apertures by using of differences between aperture area changes of the grayscale or chroma of carbonate rock and the surrounding rocks in imaging logging data. Contour extraction and contour tracing can extract the aperture boundary effectively, and calculate the aperture parameter which is unable to get quantitatively in common logging. Dealing with actual data, this method is confirmed to have a high precision.

Abstract: Because of oolitic hematite micro-fine disseminated and complex structure and other characteristics, has been considered the world's mineral processing problems. This paper studies the use of its current situation in China and some traditional sorting techniques such as strong magnetic separation - reverse flotation, flocculation - intensity magnetic separation, magnetic roasting - magnetic, and discuss an efficient sorting technique - the deep reduction, which has important practical significance for oolitic hematite sorting.