發(fā)布時(shí)間：2018-02-02 17:19

  本文關(guān)鍵詞： 梨樹斷陷 北部斜坡帶 沉積體系 營城組二段　出處：《中國地質(zhì)大學(xué)(北京)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：營城組是梨樹斷陷北部斜坡帶的主力油層,前人已對該區(qū)營城組構(gòu)造演化、烴源巖分布、層序地層劃分等做了大量研究工作,并取得豐碩成果。但在營二段物源及沉積體系等方面研究程度較低,這極大地制約了該區(qū)的油氣勘探與開發(fā)。本文通過巖芯觀察、鉆測井?dāng)?shù)據(jù)分析和三維地震資料解釋處理等方式,對營二段物源體系分布和沉積微相展布特征進(jìn)行詳細(xì)研究。將營二段劃分為SG1、SG2和SG3三個(gè)砂層組。其中SG1砂組砂巖含量較高,顆粒較粗,砂體疊置方式以進(jìn)積為主;SG2砂組砂巖粒度較細(xì),以泥巖夾砂巖沉積為主,且泥巖顏色深,砂體疊加方式以退積-加積為主;SG3砂組砂巖顆粒變粗,砂體表現(xiàn)為進(jìn)積疊置方式。綜合來看,北部斜坡帶營二段各砂層組地層厚度均呈現(xiàn)出“東薄西厚、北薄南厚”的特點(diǎn),推測沉積中心位于研究區(qū)西南部。通過對重礦物、礫巖含量以及泥巖顏色分布特征綜合分析發(fā)現(xiàn),營二段不同時(shí)期物源方向略有不同:SG1砂組物源主要來自盆地北部和北西部;SG2砂組受北部物源影響較大;SG3砂組則主要受北部和東部物源的作用。在研究區(qū)內(nèi)共識別出以下六種沉積微相:辮狀河三角洲前緣水下分流河道、河口壩、水下分流間灣、濱淺湖灘壩、砂泥坪和濱淺湖泥。營二段主要發(fā)育在水體較淺環(huán)境中,除去廣泛分布的濱淺湖泥質(zhì)沉積之外,SG1砂組水下分流河道和河口壩微相發(fā)育;SG2砂組沉積時(shí)期湖盆范圍增大,以濱淺湖亞相沉積為主,常見灘壩微相沉積;SG3砂組主要發(fā)育辮狀河三角洲前緣河口壩和水下分流間灣微相。綜合物源體系分布和沉積相展布特點(diǎn),明確了研究區(qū)營二段各砂層組沉積時(shí)期的沉積演化特征。SG1時(shí)期,湖水深度淺,北部辮狀河三角洲前緣砂體廣泛分布,并向南進(jìn)積;SG2時(shí)期,湖盆水體范圍擴(kuò)大,北部辮狀河三角洲前緣砂體向北后退,展布范圍相對減小,研究區(qū)南部大面積發(fā)育濱淺湖泥質(zhì)沉積;SG3砂組沉積時(shí)期,湖平面有所下降,辮狀河三角洲前緣砂體在北部呈帶狀分布特征�？v向上,辮狀河三角洲前緣砂體發(fā)育具有繼承性和弱旋回性的特征。
[Abstract]:Yingcheng formation is the main oil layer in the northern slope zone of Lish fault depression. Many researches have been done on the structural evolution, hydrocarbon source rock distribution and sequence stratigraphic division of Yingcheng formation in this area. But the study on the provenance and sedimentary system of the second member of the Yingshan formation is relatively low, which greatly restricts the exploration and development of oil and gas in this area. The distribution of provenance system and the distribution of sedimentary microfacies in the second member of the Ying formation are studied in detail by means of drilling log data analysis and 3D seismic data interpretation and processing. The second member of the formation is divided into SG1. SG2 and SG3 sand formation, among which SG1 sand group has higher sandstone content and coarse grain, and the sand body superposition mode is mainly precession; The sandstone of SG2 sand formation has fine granularity, mainly mudstone intercalated sandstone deposit, deep mudstone color, and sand body superposition mode is mainly retrogradation and accretion. The sandstone grains of SG3 sand formation become thicker, and the sand body appears to be progressive and superimposed. In a word, the formation thickness of each sand formation in the Ying2 member of the northern slope belt shows the characteristics of "east thin west thick, north thin south thick". It is assumed that the sedimentary center is located in the southwest of the study area. It is found that the characteristics of heavy minerals, conglomerate content and mudstone color distribution are analyzed synthetically. The provenance direction of the second member of the Ying formation is slightly different in different periods, and the provenance of the sand formation mainly comes from the northern and western parts of the basin. The SG2 sand formation is greatly affected by the northern provenance. In the study area, the following six sedimentary microfacies were identified: braided river delta front underwater distributary channel, estuarine dam, underwater distributary bay, shoreside shallow lake dam. Sand flat and shore shallow lake mud. The second member of the camp mainly developed in shallow water environment, except for the widely distributed shallow-lake muddy sediment, the SG1 sand formation developed microfacies of underwater distributary channel and estuarine dam. During the sedimentary period of the SG2 sand formation, the lacustrine basin was enlarged, mainly by the shore-shallow lacustrine subfacies, and by the common beach and dam microfacies. The SG3 sand formation is mainly composed of braided river delta front estuarine dams and interbay microfacies of underwater distributary. The distribution of the complex provenance system and the distribution of sedimentary facies are also studied. The sedimentary evolution characteristics of each sand formation in the second member of the study area. SG1 period, shallow lake depth, wide distribution of sand bodies in the north braided river delta front, and southward progradation. During the SG2 period, the lake basin water area expanded, the north braided river delta front sand body retreated to the north, and the spreading range decreased relatively. The southern part of the study area developed a large area of shallow-lake muddy sediments. During the sedimentary period of the SG3 sand formation, the lake level decreased, and the braided river delta front sand bodies showed zonal distribution in the north, while the longitudinal development of the braided river delta front sandbodies was characterized by inheritance and weak cyclicity.
【學(xué)位授予單位】：中國地質(zhì)大學(xué)(北京)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：P618.13
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本文編號：1485048