The Productivity Research On New Reservoir Area Of S₃ In Niu35-20 Block

Niu 35-20 block of Niuzhuang oilfield is tectonically located in gentle slope zone of the northwest Niuzhuang subsag, which is a turbidite sandstone oil reservoir with normal pressure and low permeability. This study is designed to use the out-station 3D data of prestack time migration of this block in the eastern Dongying in 20009 to subtly describe the sand body, evaluate the productivity of the block, study the development paradigm of low permeability oil reservoir and complete the construction scheme of the productivity of the block.First, in this research, it can accurately determine whether reflection can represent the main sand body. By refining traditional desanding test, sand can be removed one by one so as to observe the variation characteristics of phase, find the sand which play a leading role in seismic response and confirm the reliability of analysis by removing sand with positive and negative polarity. Through research, there are three reservoir description methods with the dominant technique of ―refining sand remove‖: formation thickness method, phase tracking method and phase tracking method with LPM prediction method, which break through the barrier of reservoir prediction in this study area. Second, combined the new method of reservoir prediction with sand body distribution, drilling and logging data can be used to study the distribution of single sand body, predict the area and effective thickness of three sand bodies and get the OOIP is 353.8×104t. Third, the character of trial production in this area is clearly understood and the geological and technological reason of low productivity of a well is defined. The research shows that productivity can be increased sharply unless the half-length of the fracture is between 150 m and 200 m. Forth, this research has improved the development idea of ―imitation horizontal well‖ in low-permeability reservoirs and studied the reservoir engineering parameters, such as strata, development mode, well pattern and spacing. In order to arrange the imitation horizontal well pattern, the optimized row spacing is between 200 m and 220 m, while the optimized well spacing is between 550 m and 600 m.The productivity construction reservoir engineering was planned for Niu 35-20 block, which designed 18 production wells, 11 injection wells and improved the productivity by 4.1×104t. This thesis shows that the basis of the productivity construction for Niu 35-20 block is subtle reservoir prediction, the emphasis is the assurance of OOIP, the key is productivity increasing by massive fracturing and the innovation is the improvement of development design of the ―imitation horizontal well‖ in the low-permeability reservoirs. After implementation, the results show that Niu 35-20 block capacity building programs is of evident development effect. It can be a better guidance to other similar turbidite oil reservoir construction.