滨北地区青一段油气向下“倒灌”运移距离和层位的定量研究

The quantitative research of the downward migration distance and target horizons of K_1 qn_1 oil and gas in Binbei area

为了研究滨北地区青一段烃源岩所生成油气向下"倒灌"运移的层位,对油气向下"倒灌"运移机制及条件进行了研究,认为滨北地区扶杨油层同时具备2个条件:①青一段烃源岩目前具有足够大的超压;②存在连通青一段烃源岩和扶杨油层的T2断裂,青一段烃源岩生成的油气能够在超压的作用下在古近纪末期通过T2断裂向下伏扶杨油层中"倒灌"运移。利用三肇地区14口井资料中青一段古超压同其各自油水界面深度之间的关系,建立了油气向下"倒灌"运移距离同超压之间的拟合公式,在滨北地区青一段古近纪末期泥岩超压恢复的基础上,得到滨北地区青一段烃源岩生成的油气向下"倒灌"运移的最大距离为530m,而且在可以运移范围之内大部分地区通过扶余油层进入杨大城子油层。扶杨油层油井均分布于青一段烃源岩生成的油能够向下"倒灌"运移分布范围内及附近,这表明油向下"倒灌"运移范围及层位控制着滨北地区扶杨油层油藏形成、分布范围和层位。青一段烃源岩生成的油气向下"倒灌"运移范围应是滨北地区下一步勘探的有利区块。

Migration horizons downward of oil and gas from K1 qn1 source rock in Binbei area was recognized through researching the mechanism and condition of oil and gas migration downward.It was considered that two conditions must present in F,Y oil layers;enough overpressure and the T2 faults connecting K1 qn1 source rock and F,Y oil layers.Oil and gas from K1 qn1 source rock could migrate downward into F,Y oil layers under overpressureal the end of Eogene.Bused on the relationship of 14 wells palaeopressures and ...