STATIC CHARACTERISTICS ANALYSIS OF STRIKE-SLIP FAULTS IN BONAN SEGMENT OF TAN-LU FAULT ZONE

The Bonan segment of Tan-Lu fault zone is mainly located in the south of Zhangjiakou-Penglai fault, which is composed of three main strike-slip fault zones near parallel,NE15°-30° strike. The three faults are composed of 2 ~ 3 main faults, the right-lateral strike-slip extension effect is obvious.

The east branch is the eastern boundary of the Huanghekou sag and Laizhouwan sag, which is composed of three branch faults. Dongzhi No.1 fault is inclined to SE and dip angle is 70 ° -80 °. Flower-like structures developed. The right-lateral strike-slip began at the end of Es4. Dongzhi No.2 fault is upright, cutting the early extensional shovel fault, forming a strike-slip-extensional superimposed fault system ; the cutting strata of Dongzhi No.3 fault are shallow, and the cutting of Paleogene strata indicates that the fault property transits from extension to strike-slip.The middle branch passes through the middle part of the Huanghekou Sag, forming the western boundary of the Laizhouwan Sag, which is composed of two left-order branch faults. The characteristics of deep branch faults are similar. The main strike-slip fault section is steep and NW-trending, with obvious negative flower-like structure, and obvious right-lateral strike-slip occurred in Paleogene. Shallow Zhongzhi No.2 from south to north continuous development, Zhongzhi No.1 north and south ends of development, the central is not obvious.The west branch is composed of three branch faults with poor continuity, part of which merge to the south and the middle branch. The development of the No.1 and No.3 secondary faults of the west branch can form a multi-stage Y-shaped combination with the main fault. The No.2 secondary fault of the west branch of Laizhou is not developed, indicating that the west branch has the extension property earlier, and then gradually shows the right-lateral strike-slip, and the strike-slip is weak.

The lateral distribution of strike-slip faults often forms obvious strike-slip transition zone or central structural ridge, which has a good control effect on the distribution of reservoir sand bodies. Therefore, it is of great significance to study the characteristics of strike-slip faults in Bonan section of Tan-Lu fault zone to reveal the distribution law of oil and gas in this area.