The first major breakthrough of Well Shacan 2 in exploration of the Lower Paleozoic carbonates promotes the successive discoveries of Tazhong

Tahe and Hetianhe oilfields and continuous innovation of exploration theory of large fields. And the hydrocarbon accumulation theory of carbonate reservoir is also gradually put forward. The researches on hydrocarbon accumulation conditions and typical reservoirs in the Lower Paleozoic show that the formation and distribution of large carbonate fields are controlled by the temporal-spatial combination of stable paleo-uplifts and slopes

several heterogeneous carbonate reservoirs

abundant oil sources and multiple periods of hydrocarbon accumulation. The south slope of Shaya uplift is a complex fractured-vuggy reservoir system formed due to the modification by the Caleton-Hercynian karstification and multi-staged hydrocarbon charging from Manjiaer and Awati depressions. Single fractured-vuggy reservoir has re-latively independent oil

gas and water system. These reservoirs are superimposed vertically and connected laterally with inhomogeneous oil enrichment. Katake uplift in the central of Tarim Basin possesses the typical characteristics of composite hydrocarbon accumulation. The gas oil ratio decreases from the Cambrian to the upper formations and the patterns of hydrocarbon enrichment are more complicated than that in Tabei. The hydrocarbon accumulation is characterized by lateral zonation

vertical layering

incharging in multi-places and accumulation in relative structural highs. Hetian paleo-uplift is one of three lower Palezoic uplifts with favorable hydrocarbon accumulation conditions. Yubei Ordovician reservoir was discovered recently in the Hetian paleo-high and it was an uneven karst fractured-vuggy carbonate reservoir system. However

the hydrocarbon accumulative conditions and patterns are still poorly understood. The south slope of Shaya uplift and its surroun-ding slope areas

Katake uplift and the northern slope Shunnan-Gucheng areas are potential target areas for exploration of the Ordovician

while Shuntuoguole uplift

Maigaiti slope

Madong fault belt of Tanggubasi depression

and Tabei

Tazhong-Bachu Cambrian-Ordovician deep formation area are the important areas for future exploration.