Reservoir Detection Behind Casing And Evaluation Method

Reservoir detection behind casing can obtain reservoir resistivity information, whichwould provide important basis for maintaining oil exploration and reservoir evaluation.However, the breaking of casing has a great influence on the performance of the traditionalthrough casing detection, which has a slow measuring speed and thereby cannot achieve fastand accurate detection. In order to solve this problem, this paper presents a novel inductionbased Reservoir detection method behind casing.This paper firstly introduces the basic principle of the transient electromagnetic method(TEM). The characteristic of transmit and receive coil is analyzed and the model of TEMbased Reservoir detection system behind casing is established. Based on this, the throughcasing detection system is designed and realized. Furthermore, the key technologies of theproposed system such as transmit and receive coil, transmit waveform, receive circuit,Photoelectric coding sounding and Natural gamma based depth correlation method areanalyzed.This paper then investigates the response of the through casing detection and theinfluences of the non-ideal factors. The response of the transient magnetic dipole source isderived and the effects of the steel casing are analyzed. In order to improve the stability of theproposed system, a long term coherent integration based method is proposed to suppress thenoise part. Simulation results show that the proposed method can improve the SNR anddetection performance effectively.Finally, the reservoir evaluation behind casing is introduced and a large amount of fieldtests are carried out. Simulation, experiments, and field tests show that the proposed methodcan achieve the through casing resistivity measuring and can provide important theoretical andexperimental basis theories and s of Reservoir detection behind casing.