Quantitative Estimate of Hydrocarbon Loss During Migration

Xiaorong Luo¹, Bo Zhou¹, Ping Hou¹, Sumei Li², and Xiongqi Pang^2
1 Key Laboratory of Mineral Resource, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
² Key Laboratories for Petroleum Formation Mechanics, Chinese Ministry of Education, Petroleum University, Beijing, China

Estimate of hydrocarbon loss during migration is critical to petroleum resource assessment based on mass balance. We conducted physical and numerical experiments to qualitatively simulate expulsion of water by migrating oil in glass tubes filled with glass beads and to quantitatively simulate lateral migration processes in a basin scale, and estimated proportions of oil loss along different parts of the migration pathway. The pathway within carrier beds from the point of hydrocarbon expulsion to the trap is divided into three parts: the vertical and lateral pathways within the area limit of effective source rocks (W1), and the lateral pathway in the area beyond the limit (W2). Following Hirsch & Thompson's (1995) work, we proved that the proportion of oil loss along the vertical pathway (Sc) ranges from 0.05 to 0.80, depending mainly on unit scale, pore size, grain wettability and migration force. For sandstone carriers in a basin scale, the proportion is nHSc along vertical pathway (where n is the number of units; H is normalized carrier thickness within W1), and is about nSc along lateral pathway within W1. Simulation results show that the proportion of oil loss along W2 decreases with the distance from the margin of W1, and the loss in W2 is two orders of magnitude less than that in W1. Model application to the Bamianhe Field in Bohaiwan Basin, eastern China indicates that about 7.5% of the hydrocarbon expelled from source rocks were lost along migration pathway from kitchen to trap.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005