地層格架內(nèi)的砂體展布
(1. 中南大學(xué) 有色金屬成礦預(yù)測(cè)教育部重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083；
2. 中南大學(xué) 地球科學(xué)與信息物理學(xué)院，長(zhǎng)沙 410083；
3. 中國(guó)石油長(zhǎng)慶油田公司 超低滲透油藏第四項(xiàng)目部，慶陽 745000)
摘 要: 基于傳統(tǒng)的層序地層學(xué)理論，利用巖心、露頭、測(cè)井和地震等資料，開展S75區(qū)石炭系卡拉沙依組層序地層格架研究。識(shí)別出各類層序邊界與層序內(nèi)部的初始海泛面和最大海泛面，對(duì)準(zhǔn)層序進(jìn)行識(shí)別和劃分，將卡拉沙依組劃分為3個(gè)三級(jí)層序，識(shí)別出低位體系域、海侵體系域和高位體系域。由于受多期河道砂體相互切割疊加的影響，卡拉沙依組SQ2和SQ3層序水下分流河道砂體的連通性較好，特別是SQ2層序三角洲前緣沉積時(shí)期。Csq1層序的垂向上可發(fā)育多個(gè)沖刷面，主要砂體發(fā)育在潮間帶的潮道中；Csq2層序低位體系域砂體主要發(fā)育在扇三角洲分流河道，Csq2層序海侵體系域砂體主要在潮道和砂泥混合坪中發(fā)育；Csq3層序砂體主要在潮間帶的潮道中發(fā)育。從卡拉沙依組3個(gè)層序的砂體發(fā)育演化來看，T806K~TK842井一帶、TK711~TK729井一帶及S75~TK736一帶是研究區(qū)砂體發(fā)育較集中的區(qū)域。
關(guān)鍵字: 塔河油田；S75井區(qū)；卡拉沙依組；層序地層格架；體系域；砂體展布
stratigraphic framework of Carboniferous Kalashayi Formation in
S75 well area, Tahe Oilfield
（1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals, Ministry of Education,
Central South University, Changsha 410083, China;
2. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
3. The Fourth Low-permeability Reservoir Department, Changqing Oilfield Company, China National Petroleum Corporation,
Qingyang 745000, China）
Abstract:Based on the traditional sequence stratigraphy theory, core, outcrop, well logging, seismic and other data were used, and the sequence stratigraphic framework study of Carboniferous Kalashayi Formation in S75 well area was carried out. The types of sequence boundaries, the first flooding surface and the maximum flooding surface were identified, the parasequence was identified and classified, Kalashayi Formation was divided into three third-order sequences, in which lowstand system tract, transgressive system tract and highstand system tract were identified. Due to the effect of multi-stage channel sand body cutting, the connectivity of the underwater distributary channel sand body in SQ2 and SQ3 sequences period is better, especially SQ2 delta front deposition period. The sand bodies in vertical direction of Csq1 sequence can develop some scour surfaces, the sand bodies are mainly developed in tidal channel of the intertidal. The sand bodies of Csq2 sequence lowstand system tract are mainly developed in fan delta branch river, the sand bodies of Csq2 sequence transgressive system tract are mainly developed in tidal channel sand and mud mixed flat. The sand bodies of Csq3 sequence are mainly developed in tidal channel of the intertidal zone. According to the sand bodies development and evolution of three sequences in Kalashayi Formation, T806K−TK842 well area, TK711−TK729 well area and S75−TK736 wells area are the sand bodies development concentration region.
Key words: Tahe Oilfield; S75 well area; Kalashayi Formation; sequence stratigraphic framework; system tract; sandstone bodies distribution
