(ZHANG Xiumei from Ultrasound Physics and Detection Lab) National Natural Science Foundation(NNSF) Key Project of "Borehole Wave-field in Inhomogenous, Anisotropic and Porous Formation" from 2006 to 2009 undertaken by Ultrasound Physics and Detection Lab, CAS Institute of Acoustics, Institute of Resource and Information, China University of Petroleum (Beijing), together with Institute of Physics, Jilin University was successfully accomplished.

Professor Zhang Hailan, the leader of the project reported on behalf of the project team at the project evaluation meeting. He pointed out that the content of this project includs many basic research topics difficult but critical for many practical problems in oilfields. However, research on these topics would not bring economic benefit immediately and hardly supported by oil companies. The project supported by NNSF focused on some typical basic issues, was important to improve the level of researchers and the capabilities to resolve difficult problems encountered by oil companies in practice.

Achievements during the past four years were plentiful, including theoretical analysis on wave modes in boreholes, numerical simulation algorithms, complicated media model, scaled borehole laboratory experiments and application of borehole acoustic wave propagation theory. The project team also published dozens of academic papers on many well-known journals and symposiums.

After the reports, evaluation experts discussed with the project team. Finally, the project won outstanding performance of six A plus three B. The experts gave the following opinions: the project derived important scientific problems from acoustic logging practice, several new approaches in analyzing wave modes excited within boreholes were presented, studies were conducted on development of new algorithms in simulating acoustic wave propagation, and their applications were successful. New ideas and research methods were put forward in formation modeling, anisotropic formation samples were made and scaled laboratory experiments were carried out. The project achieved fruits in theoretical analysis, numerical and experimental simulations, developments of new logging equipments, etc..

Meanwhile, through organization, implementation and conclusion of this project, many consensus and experience were achieved: Firstly, the project played an important role in organizing a comprehensive research team on borehole acoustics. Three participant institutions have been worked on borehole acoustics for many years, and were characteristic by their own advantages. All of them have undertaken many research works closely related to the production of oil, entrusted by many oil companies over the past years. Secondly, the project played a catalytic role to promote academic exchanges between the participants. During the course of the project, project team paid special attention to enhance academic exchanges, in addition to regular communications, they also held annual academic discussion with more than twenty oral reports each time, which ensured the progress of the project. Specially, discussion held in 2008 attracted many domestic institutions and enterprises.