Petroleum System Modeling for Exploration Aims in the Riphean and Vendian Sedimentary Sequences of the Lena-Tungusska Basin

Lopatin, Nikolai ¹; Zubairaev, Saidy ²; Tikhonov, Ilya ³; Kalabin, Vasily ⁴; Emets, Tamara ⁵; Sitar, Ksenia ⁶; Bakaikin, Sergey ⁷
(1)Rosnedra, VNIIgeosystem, Moscow, Russian Federation. (2) Rosnedra, VNIIgeosystem, Moscow, Russian Federation. (3) Rosnedra, VNIIgeosystem, Moscow, Russian Federation. (4) Rosnedra, VNIIgeosystem, Moscow, Russian Federation. (5) Rosnedra, VNIIgeosystem, Moscow, Russian Federation. (6) Moscow State University, Moscow, Russian Federation. (7) Rosnedra, VNIIgeosystem, Moscow, Russian Federation.

The main purpose of this study was identification the oldest oil source rocks and petroleum system modeling for Exploration aims in the southern part of the East Siberia. The collection of the core samples was included more than 4000 from Urubcheno-Tokhomo, Kuymba, Madrin, Baikit, Taimba, Ust-Kamo, Ajavin, Kopoktin and others oil fields. Also, 47 oil samples and 120 extractions from probably source rocks. The analytical procedures included measurements of the bulk geochemical parameters: by Rock-Eval 6; whole oil, condensates and extracts for GC and GC-MS, vitrinite reflectance. For Basin Modeling were used: “PetroMod-1D” and “Temis Suite-2D”.

This study has been shown that we have active source rocks only in Rephian part of the sedimentary sequences:

- Upper Riphean Iremeken dolomitic black shale (R3) is unique very rich oil source rock formation.

- Upper Riphean Ajan black shale Fm (R3).

- Middle Riphean (R2/R1) Madrin black shale Fm with residual oil generation potentia.

- Lower Riphean Vedreshev black shale Fm (R1).

The main pod of active source rocks located in the Kimchukan depocenter, the conjugate zones between the southern part of the Kureyka syneclize and Baikit and Nepa-Botuoba anteclizes, where widely distribute the main source rock - Iremeken Fm with favourable catagenesis level (R0=0,82-1,20%) for continuation of the HC-generation in the late Paleozoic to Early Mesozoic time, and effective sublateral migration pathways along the regional Riphean/Vendional interrupt paleosurface (Lower Riphean).

The Iremeken carbonate-shale Fm is characterized by high transformation ratio of kerogen into petroleum, TR≈65-70%, that corresponds to the late zone of oil generation. Madrin and Vedreshev source rocks Fm are characterized by very high transformation ratio, TR≈85-95%, in such conditions only gas is generated. In the area of Kimchukansky depocenter hydrocarbon generation density takes the following: Iremeken formation - 20,5 t HC/m² and realization of the potential far from over, Madrin Formation - 7,5 t HC/m² and realization of potential was completed in early Paleozoic, Vedreshev formation - 9,0 t HC/m², realized mainly in the Late Riphean-Early Paleozoic time.

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.