Central uplift belt of Dongying depression has been formed as a result of joint action of the extensional fault-flexure folding of Chennan fault and diapirism of plastic salt-mud layers controlled by regional and local structural stress fields. Development levels and combination features of structures in the central uplift belt are spatially quite different

due to differential actions of various factors

such as distribution of salt-mud layers

sedimentary features when the faults were active and regional tectonic stress field. The central uplift belt can be divided into 3 structural zones

i.e. Xinzhen

Dongying and Liangjialou-Xianhezhuang structural zones. Distributions of oil and gas are closely related to faulting in the central uplift belt:(1) hydrocarbons have mainly been accumulated in shallow reservoirs as secondary pools when the strength of faulting changed from weak to strong; (2) hydrocarbons have mainly been accumulated in deep reservoirs as primary pools when the strength of faulting changed from strong to weak; (3) hydrocarbons have been accumulated both in shallow and deep reservoirs constitute complex oil-gas accumulation zone with multiple oil-bearing series and various types of oil pools when the strength of faulting changed first from weak to strong and then from strong to weak.