奥里诺科重油带构造成因分析

Genesis analysis of fault structures in the Orinoco heavy oil belt

奥里诺科重油带是目前世界上唯一一个还基本未开发的大规模重油富集带,它位于东委内瑞拉盆地边缘隆起带,总体是一北倾单斜,其上主要发育E-W向、NEE向和NE-SW向三组断裂,且以张性断裂为主,其中有一条北东向区域性大断裂将奥里诺科重油带在平面上划分为两大构造区,其各自的构造特征不同.奥里诺科重油带之所以有这样的构造特征是与其所处的大地构造背景和加勒比板块与南美板块发生斜撞等一系列作用有关的.本文在总结奥里诺科重油带构造特征同时,对其成因进行了深入分析,以便对奥里诺科重油带构造解释和油气藏的控制因素分析起到指导作用.

The Orinoco heavy oil belt is the unique undeveloped area with large scale enriched heavy oil in the world at present,It is located in the marginal uplift belt of the eastern Venezuela Basin. It is overall a monoclinal structure dipping to south, on which three group faulted structures with the directions of E-W, NEE, and NE-SW are developed, and they are tensional faults. The Orinoco heavy oil belt has been divided into two tectonic zones by one regional fault with the trend of NE in the plane, and the characteristics are different in the two tectonic zones. The faulted structure of the Orinoco heavy oil belt is relatied to a series of processes, such as its location and the oblique collision between the Caribbean and South American plates. In this paper, the characteristics of the faulted structure are summarized and, at the same time, the formation cause of the fault structure of the Orinoco heavy oil belt is analyzedin detail, so as to play a guide role for the analysis of the structure interpretation and the reservoir controlling factors of the Orinoco heavy oil belt.