根据东营凹陷民丰地区烃源岩生烃史、储层受热史及储层沥青分布特点,综合天然气成藏地质背景,分析了该区中深层天然气藏的成因类型及特征,建立了天然气成藏模式.研究表明:民丰地区已发现的深层天然气主要为来源于沙四下亚段烃源岩的油型裂解气,存在干酪根裂解气直接进入圈闭形成气藏、干酪根裂解气充注古油藏形成气侵富化型气藏、古油藏裂解形成气藏3种成因类型的天然气藏.受烃源岩生烃演化的控制,3种成因类型的气藏在空间上具有一定的展布规律,即:埋藏较深的洼陷中心区形成以干酪根裂解气为主的纯气藏,有部分古油藏裂解气；斜坡带地区聚集以气侵效应为主的气侵富化型气藏；埋藏较浅的斜坡边缘地区仅存在晚期充注的油藏；从洼陷区到斜坡高部位,形成了纯气藏、油气混相、油藏的分布模式.%According to hydrocarbon generation history of gas source rock, reservoir thermal history and reservoir bitumen of Minfeng area in Dongying sag, comprehended gas accumulation geological background, the genetic types and characteristics of middle-deep gaspools are analyzed, and the gas accumulation model is set up. The middle-deep gas having been discovered is mainly cracked gas and comes from the lower Es4 source rock. There are three genetic types and gas accumulation models: kerogen-cracking gas directly entered traps and formed gas pool, kerogen-cracking gas infilledpaleo-reservoir and formed gas invasion enrichment gas pool, paleo-reservoir oil cracked and formed gas pool. Be controlled by the evolution of the source rock, the distributional characterization of three types of the gas reservoir is obtained. The central of the sag is mainly accumulated with pure gas reservoir composed by cracked gas from kerogen, and some cracked gas generated from ancient oil reservoir. Slope zone is accumulated with gas invasion enrichment gas pool. There is only oil pools charged at late stage on the relatively shallow slope edge. From the central area of sag to the high slope area, the distribution model that gas, oil gas mixed phase and oil coming in turn forms.
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