Full text loading...
-
Linking The Diagenetic Evolution To Poroperm Development In A Paleozoic Carbonate Reservoir Analog, Northern Vietnam
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, EAGE Conference on Reservoir Geoscience, Dec 2018, Volume 2018, p.1 - 5
Abstract
A lot of exploration wells have been drilled to test “buried-hill” plays in fractured Paleozoic carbonates in offshore northern Vietnam with either dry holes or showing low flow rates. To better understand diagenesis-related poroperm development and how can we target more successfully in this complicated reservoir, a detailed geological characterization of fractured Paleozoic carbonates was undertaken in a quarry outcrop in the Northern Vietnam. This work integrates the results of detailed mapping and interpretation of lithologies and fracture orientations, along with detailed petrographic and isotopic analyses and leads to the following conclusions: (1) Significant levels of poroperm in fractured Paleozoic carbonates in the region are mostly confined to NE-SW fracture sets created and enlarged in the telogenetic realm relating to uplift in a stress field created by movement of the Red River Fault. (2) Equivalents to this style of diagenesis likely occur in subsurface as potential fractured Paleozoic reservoirs in the nearby offshore. (3) Successfully exploring and developing such reservoirs will require directional (not vertical) wells and a better rock-based understanding of the controls, orientations, timings of major fracture events (requires outcrop and core-calibrated FMI interpretation). (4) Poroperm predictions in subsurface counterparts require an improved understanding of fluid evolution and the relative timing of the various diagenetic events that can occlude or enhance porosity and permeability in both matrix and fractures (requires detailed petrographic study tied to texture-aware isotope sampling of cuttings or core).