Pipe jacking project is regarded as a technology of nonexcavation pipe jacking construction project, which has the most prominent feature of adaptability. The cutter head is one of the key components of the jacking machine crossing oilgas pipelines, which major function is to accomplish crushing and peeling of rock soil of tunnel face, and takes a key role in digging function. Because of the difficulty of changing cutters and the complexity of the work environment, there is a high demand for the intensity of the cutter head. A corresponding cutter design program is established based on the special geology of the construction domain, and the torque and thrust calculation methods are given. Besides, the finite element model is established under the help of the ANSYS(finite element analysis software), so that the stress, strain, and strength reserve distribution are obtained. The analysis results show that the greatest equivalent stress appears at the interface between corbel and transmission shaft. The greatest stress is 37.6 MPa and the largest distortion is 0.06 mm.The result of this research provides effective theory evidence for optimal structural design of the cutter head.

There are many problems in the development process of the low permeability oilfields including water injection difficulty, high water flooded degree, low utilization efficiency of injected water and gas channeling of gas injection. Through a large number of laboratory physical simulation experiments and tests, the best CO2foam system was selected out for a low permeability blocks CO2foam flooding in Jilin oil field. The stability, foaminess, injectivity and applicable scope of the permeability of three systems were conducted. The results showed that the three kinds of foam agent all had good foaminess and stability, and all of them could be injected within the range. When the temperature rose from 45 ℃ to 100 ℃, the halflife of foam systems sharply reduced, and the stability of them turned bad. In the three foam systems, FP388 was the optimal one which had best foaminess and comprehensive performance.