蓬莱9-1构造花岗岩古潜山油气成藏条件与成藏模式

发布时间：2018-05-07 20:00

本文选题：蓬莱9-1构造 + 构造演化　；参考：《成都理工大学》2015年硕士论文

【摘要】：蓬莱9-1油田位于渤海海域庙西北凸起上,是近年来中国近海首次发现的一个以花岗岩古潜山风化壳为储层的大型油田。目前国内针对燕山运动期中生代侵入的花岗岩古潜山油气如何成藏且成藏规模之大研究非常匮乏。本文综合利用磷灰石裂变径迹模拟、岩心观察、薄片鉴定、测井资料分析、生物标志化合物对比、包裹体记录等技术手段,结合蓬莱9-1构造地质背景,对潜山的构造演化、花岗岩储层特征、油源对比及成藏条件进行了详细剖析,恢复了蓬莱9-1构造花岗岩古潜山油气成藏过程,并建立了油气成藏模式。主要取得以下研究成果:(1)在距今164Ma时,花岗岩岩浆底辟式侵入变质岩中,之后潜山花岗岩主要经历了164Ma~(55.0~53.5)Ma的快速隆升剥蚀期,(55.0~53.5)Ma~(34.0~33.5)Ma的构造稳定期,距今(34.0~33.5)Ma~23.3Ma的再次快速隆升剥蚀期,以及距今23.3Ma以后的缓慢沉降期,形成花岗岩古潜山。(2)花岗岩古潜山风化壳呈现出明显的分带性,从上至下,依次为砂质风化带、砾质风化带、裂缝带和基岩带,储集空间类型主要为粒间孔、溶孔、微裂缝及显微裂缝。在平面上,根据储层厚度、孔隙度和储集空间类型分为储层发育区、储层欠发育区和储层不发育区,储层越发育的地区,总的油层厚度也较厚。储层发育区主要分布在蓬莱9-1构造的东南部,也是古潜山风化壳的高部位,受风化、剥蚀作用最强烈,由东南向西北方向,储层发育成都逐渐降低。(3)原油受生物降解严重,降解程度达到7级以上,已不能使用饱和烃生物标志化合物来分析油源,但从蓬莱9-1油田潜山原油和油砂样品的甲基三芳甾烷参数可以看出潜山原油主要为沙一段与沙三段混源油,为Es1+Es3型原油;南部潜山的PL9-1-11、PL9-1-12、PL9-1-14井区潜山原油有东营组烃源岩生成原油的后期充注,表现为Es1+Ed型原油。(4)蓬莱9-1潜山花岗岩油源来自于渤东南洼沙河街组及东营组烃源岩,均为优质烃源岩。沙河街组烃源岩在馆陶组沉积末期进入生烃门限,明下段沉积末期开始进入大量生排烃阶段,而现今已达到生油高峰期。东营组烃源岩在明下段沉积末期开始进入生烃门限,而现今处于大量生排烃阶段。潜山油气以不整合面-断层为输导系统,油气运移主要是通过不整合面上、下的“底砾岩连通孔隙”及“风化、淋滤带裂缝-溶蚀孔洞”两类高效运载层运移输导。潜山油气藏的直接盖层是上覆馆陶组地层,而馆陶组沉积的底部是一套水下分流河道间湾沉积,紫红色泥岩或紫褐色泥岩的沉积,刚好在潜山不整合面之上,它的厚度决定了潜山油气能否较好的保存和油气藏的油质。(5)距今(55Ma~53.5Ma)~23.3Ma,花岗岩区呈现洼地的地貌轮廓,并遭受风化剥蚀形成储层,渤东凹陷新近系沙河街组及东营组相继沉积;距今23.3Ma~12Ma,馆陶组沉积覆盖于潜山之上,形成潜山油藏的直接盖层;距今12Ma-现今,沙河街组烃源岩进入大量生、排烃阶段,同时东营组开始进入生烃门限,并经过3.2Ma的油气主充注期,油气通过断层及不整合面,运聚到潜山顶部形成大型油藏。
[Abstract]:Penglai 9-1 oilfield is located in the northwestern Temple of Bohai sea area. It is the first large oil field with granite ancient Qianshan weathering crust discovered in recent years in China's offshore area. At present, the major research on how the Paleozoic granitic Qianshan oil and gas reservoirs are formed and the reservoir forming models are very scarce in China. The comprehensive utilization of this paper is made in this paper. The apatite fission track simulation, core observation, thin slice identification, logging data analysis, biomarker contrast, inclusion recording and other technical means, combined with the 9-1 tectonic geological background of Penglai, the structural evolution of Qianshan, the characteristics of granite reservoir, oil source contrast and reservoir formation are detailedly analyzed, and the ancient Penglai 9-1 tectonics granite is restored. Qianshan oil and gas accumulation process, and established oil and gas accumulation models. The main results are as follows: (1) the granite diapir was intruded into metamorphic rocks at 164Ma, after which Qianshan granite experienced the rapid uplift and erosion period of 164Ma~ (55.0~53.5) Ma, the structural stability period of (55.0~53.5) Ma~ (34.0~33.5) Ma, and now (34.0~33.5) Ma~23. The second rapid uplift and erosion period of.3Ma and the slow settlement period after 23.3Ma have formed the granite ancient Qianshan. (2) the granite ancient Qianshan weathering crust showed obvious zonation, from upper to lower, it was sandy weathered zone, gravel weathering zone, fracture zone and bedrock zone, and the reservoir space types were mainly intergranular pore, pore dissolution, micro fissure and microscopy. On the plane, according to the thickness of reservoir, porosity and reservoir space types, the reservoir is divided into reservoir development area, the reservoir is underdeveloped area and reservoir undeveloped area, the area of the reservoir is more developed, the thickness of the total oil layer is thicker. The reservoir development area is mainly distributed in the southeastern part of the 9-1 structure of Penglai, and is also the high part of the ancient Qianshan weathering crust, which is weathered and denuded. With the strongest, from the southeast to the northwest direction, the reservoir development Chengdu gradually decreases. (3) the crude oil is seriously biodegraded and the degree of degradation reaches over 7. It is impossible to use the saturated hydrocarbon biomarker compound to analyze the oil source, but from the parameters of the methyl three aryl sterane of the Qianshan crude oil and the oil sand samples of the 9-1 oil field of Penglai, it can be seen that the Qianshan crude oil is mainly The mixed source oil of Sha 1 and Sha three sections is Es1+Es3 type crude oil. The Qianshan crude oil in the southern Qianshan, PL9-1-11, PL9-1-12 and PL9-1-14, has the late filling of the Dongying formation hydrocarbon source rocks, showing Es1+Ed type crude oil. (4) the Penglai 9-1 Qianshan granite oil source is derived from the Shahe Street formation and the Dongying formation source rocks in the Bohai southeast depression, and all are the high quality source rocks. The hydrocarbon source rocks of the river block entered the hydrocarbon generation threshold at the end of the Guantao formation, and the late Ming period began to enter a large number of hydrocarbon generating and expulsion stages, but now it has reached the peak period of oil generation. The source rocks of the Dongying formation began to enter the hydrocarbon generation threshold at the end of the lower Ming period, and now in a large number of hydrocarbon generation stages. The oil and gas in Qianshan are transported with unconformable surface fault as the conduction. In the system, the migration of oil and gas is mainly carried out through two kinds of high efficient carrier layers, which are "basal conglomerate connected pores" and "weathering and leaching zone". The direct cover of Qianshan oil and gas reservoirs is the overlying Guantao formation, while the bottom of the Guantao formation is a set of underwater distributary interchannel Bay deposits and purple red mudstones. The deposition of or purple brown mudstone is just above the unconformities of Qianshan. Its thickness determines whether Qianshan oil and gas can be preserved well and oil and gas reservoirs. (5) 55Ma~53.5Ma ~23.3Ma, the granite region presented a low-lying geomorphic contour and suffered from weathering denudation to form a reservoir. The Neogene Shahe Street formation and Dongying formation in the Bodong sag were successively deposited. After 23.3Ma~12Ma, the Guantao formation was deposited over Qianshan to form the direct cover of the Qianshan reservoir, and now the hydrocarbon source rocks of the Shahe Street Group entered a large number of life and hydrocarbon expulsion stages, and the Dongying formation began to enter the hydrocarbon generation threshold, while the Dongying group began to enter the hydrocarbon generation threshold, and through the 3.2Ma oil and gas filling period, the oil and gas were transported to the top of Qianshan through the faults and unconformities to form the top of Qianshan. Type reservoir.

【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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