Summary of the AAPG Research Symposium on Lacustrine Basin Exploration in China and Southeast Asia

Abstract

In this paper, we review the work presented at the AAPG-Shengli Petroleum Administration Research Symposium dealing with lacustrine basin exploration in China and southeast Asia. This meeting, held in the fall of 1995, revealed that there has been an expansion of the available knowledge base associated with these basins. This increase in information has resulted in a better understanding of lacustrine basin-fill properties and characteristics, even though many of the causal mechanisms for these properties have not yet been established. The many papers presented suggest that there are two primary causes for economic failure within many of these basins: (1) communication between source and reservoir and (2) the limited reservoir potential within the lacustrine sequence of these basins. More effective petroleum systems are found in basins where marine sandstones are in communication with lacustrine sources. The discussions also clearly demonstrated that lacustrine basins are sensitive to environmental changes, causing complex sedimentary facies successions. Each facies, however, displays unique characteristics that can be mapped. Several presenters also suggested that within extensional lacustrine settings the stratigraphic succession follows a distinct pattern. Although most of these basins are predominantly oil prone, several lacustrine basins within the region contain significant volumes of gas. Included within these gas reserves are biogenic accumulations that appear to have formed nearly penecontemporaneously with deposition. Recent work on several of the Chinese basins suggests the possibility for immature hydrocarbon generation and expulsion in a manner different than that associated with marine type II-S kerogens. Even with the progress that this symposium revealed there are several key questions that remain, including questions associated with how technology might be used to improve the economics of many of these systems that display limited reservoir potential.