FLUVIO-LACUSTRINE DEPOSITION AND IMPLICATIONS FOR RESERVOIR DEVELOPMENT, FUYANG SANDSTONE, DAAN BLOCK, SONGLIAO BASIN, P. R. CHINA
John S. Sneider1, Andrew S. Harper2,
Tim Liu2, Susan Cao2,
and James Wang3
1 Sneider Exploration Inc
2 MI Energy Corp
3 PetroChina Jilin
Since 2001, operator MI Energy and partner PetroChina have drilled 31 wells to test the Early Cretaceous Quantou Group, Fuyu and Yangdachengzi Sandstones (FuYang Sands), which are the main reservoir objectives in Daan Field. All 31 wells are oil discoveries. Conventional core samples were taken in the FuYang interval in three wells: Da206-10, Da206E and Da207-1.
Da206-10
o Core Depth: | 1950.90 – 1960.35m |
o Porosity: | 9.6 – 19.0% |
o Permeability: | 1.6 – 7.88mD |
o Unit Thickness: | 8.9m |
o Lithology: | F-M Sandstone |
o Facies: | Distributary – Fluvial Channel |
Da206E
o Core Depth: | 1937.88 – 1940.03m | 1905.87 – 1906.14m |
o Porosity: | 6.4 – 11.6% | 2.1 – 10.3% |
o Permeability: | 0.01 – 0.82mD | 0.01 – 2.38mD |
o Unit Thickness: | 3.6m | 2.5m |
o Lithology: | Sandy Siltstone | VF Silty Sandstone |
o Facies: | Crevasse Splay | Crevasse Splay |
Da207-1
o Core Depth: | 1908.22 – 1922.26m | 1936.67 – 1955.87m |
o Porosity: | 7.4 – 13.1% | 6.5 – 13.6% |
o Permeability: | 0.18 – 2.70mD | 0.01 – 1.30mD |
o Unit Thickness: | 4.0m | 3.6m |
o Lithology: | F Silty Sandstone | F Silty Sandstone |
o Facies: | Subaqueous Channel | Subaqueous Channel |
The Daan Field FuYang Sands are interpreted to have been deposited in fluvial to shallow lacustrine environments during a relative low stand period in the evolution of the Songliao Basin, which is a Mesozoic Rift Basin. Specific facies observed in core include proximal, fluvial - subaerial distributary channel (Da206-10), proximal subaerial crevasse splay (Da206E), and distal, subaqueous channel (Da207-1). The FuYang sands were deposited by north-flowing rivers controlled by NNE-trending, down-to-the-west normal faults. The FuYang rivers emptied into relatively small, localized lakes during the Songliao basin low stand period.