| Tarakan Basin, as an important basin in Indonesia with abundant oil and gas resource, is divided into three zones from land to sea, namely inversion structure belt on land, extensive fault belt on continental shelf, and thrust belt in deep water, with respective features of hydrocarbon accumulation and distribution. It is concluded that hydrocarbon accumulation is controlled by both source rock and conduit system in Tarakan Basin. Oil and gas are mainly concentrated in favorable structures near the center of hydrocarbon generation in the shelf zone, where the Miocene coal strata is the major source rock. The conduit system is the main controlling factor for hydrocarbon accumulation in different zones. Fractures and structural sand ridges are the dominant pathway for hydrocarbon migration in the inversion structure belt, and hydrocarbons are mainly concentrated in the Pliocene and Upper Miocene structural sand ridges. The growth fault is the dominant pathway for oil and gas migration in the extended fault zone on the continental shelf, and oil and gas are mainly concentrated in the Pliocene and Upper Miocene fault blocks. Thrust faults are the dominant pathway in the thrust zone in deep water, and hydrocarbons are mainly enriched in the Pliocene thrust anticline. According to the order of exploration potential, the extensive fault belt on the continental shelf is the largest, followed by the thrust-fold belt in deep water, and the inversion structure belt on land again. |
