Source Rock And Geochemistry Characteristics Of Taisheng1Well In Sanhu Depression,Qaidam Basin

The Sanhu depression area in Qaidam basin to the southeast, geographical location in the northeastern Tibetan Plateau, which belongs to the new generation of advanced forming a large sedimentary depression, this area is the Qaidam Basin. Quaternary sedimentary center, but also the country’s largest biological field.According to Taisheng1well drilling and logging, core analysis, the Taisheng1well source rock evaluation, the following aspects of the knowledge:1.Taisheng1well TOC contents were generally higher, mainly in the0.13-23.56%. for an average of1.53%. Among them, Upper Youshashan Formation (N22) in mudstone content of TOC inO.13-12.89%, the average was1.58%; Shizigou Formation (N23) in mudstone content of TOC inO.14-23.56%. an average of1.51%. Taisheng1well N23. N22in source rock organic matter abundance limit at about0.25%.2.Taisheng1well from Upper Youshashan Formation (N22) to Shizigou Formation (N23), Qigequan Formation (Q1+2) from the lower to the upper strata reflect lake has been in the water-salt water environment, water from Upper Youshashan Formation (N22) has been since salinity is rising, more and more high salinity limit the aquatic plant growth, resulting in the Qigequan Formation (Q1+2) organic matter with a large number of terrestrial plants, less aquatic plants, organic matter type with112-Ⅲ type is the main trend. Deepl well natural gas organic matter is mainly associated with the lower aquatic organisms is related to the type of better organic matter.3.Taisheng1well organic vitrinite Ro value is<0.5and0.5-1.35%, the pyrolysis temperature of410-450C,show that thermal evolution of organic matter in the immature to mature stage.4.Taisheng1well Qigequan Formation and Shizigou Formation gas generation intensity, Upper Youshashan Formation hydrocarbon generation intensity of small. Upper Youshashan Formation the type of organic matter is good, may have a larger peak in oil. natural gas production. Biological gas production strength and thickness of dark mudstone is associated with Shizigou Formation, longitudinal groove group biological gas strength. On the same horizontal strata in Saline Lake, and the larger area of Taijinaier, Nanling hill area is the smallest.S.Taisheng1well shallow seven fountain formation of natural gas methane main origin may be of biological origin. Taisheng1well Upper Youshashan Formation (3200-3400m.3700-4200m) high methane gas may not mainly come from the biological causes, possible to heat the main role.