塔里木盆地塔河油田水离子组合及参数的平面分布与油气运移

ION RELATED PARAMETERS OF FORMATION WATER DISTRIBUTION IN THE TAIHE OILFIELD AND ITS RELATIONSHIP TO PETROLEUM MIGRATION

通过对塔河油田水离子组合及其参数的平面分布图的编制来推断油田水系统的形态、分布,并根据其参数变化梯度分析了油气运移方向。研究表明:塔河油区油田水参数的平面分布总体具有南北分块、东西分带的特征;其中,塔河1、2区三叠系油田水主要呈东西向分布,而塔河3、4、6区具有南北条状带向分布,但东西分异、南部平台区则为近东南-北东-南西向分布;7区西北部和8区可能呈南北向分布。同时,油田水分布局部呈洞穴状、桶状和其它不规则孤立或封闭流体系统;出现水动力相对强或弱的交替带或滞后区带;其离子及组合参数均指示油气运移的主导方向是自南、西南向北、北东方向。

The wide range variation of composition of formation water distributed in the different areas of the Taihe oilfield are likely to represent the different and complex system of fluid. Using the mapping of ion related parameters of formation water distribution in the Taihe oilfield, authors have tried to define forms and boundary of formation water system and determinate the direction of petroleum migration based on the gradient of ion related parameters. It is concluded that the distribution in the Taihe oilfield water shows a distinctly ＂Block form＂ along the N-S direction and ＂Zone form＂ in the E-W direction, i. e. , the Triassic formation water in No. 1 and No. 2 district of the Taihe oilfield is taken shape in E-W direction, and the ＂Zone form＂ of distribution of formation water in No. 3, No. 4, No. 6 and No. 8 , as well as the Northwest part of No. 7 are significantly present in the N-S direction with different variation tendency along theirs E-W wing, while the Southern platform in the Taihe oilfield suggests that variation of distri-bution from southeast to northeast and southwest. Besides, the distribution of formation water is locally present as isolated and closed fluid flow system in the shapes similar to cavern, barrel and other irregular forms, and it also have been found there are either intermediated zone between weak and strong water-flow movement or stagnate zone, the direction of petroleum migration is mainly interpreted as controlled from south or southwest to north or northwest in the Taihe oilfield in terms of the major ion concentration and its combined parameters.