油层套管射孔开裂的安全韧性判据

为解决油层套管射孔开裂问题，除应对射孔弹、射孔工艺以及油层套管的材质进行研究外，还应建立油层套管射孔开裂的安全韧性判据．本文分析了油层套管射孔开裂时的受力状况，运用金属动态形变原理，结合薄壁管失稳断裂的力学理论，从理论上充分论证了ＡＫＶ／σＹ作为套管射孔开裂安全韧性判据的可行性；同时，在实验室试验及油层套管实弹模拟射孔试验的基础上，建立了油层套管射孔开裂倾向与管材力学性能间的相关性判据，即对于不同钢级的油层套管，避免射孔开裂现象的安全韧性判据为ＡＫＶ／σＹ≥５．３×１０－２Ｊ／ＭＰａ．还对不同钢级套管韧性、冲击试样尺寸，试样各向异性及试验温度等与该判据相关的一些问题进行了讨论．

The Toughness Safety Criterion of Production Casing in Perforating

In order to prevent perforation cracking of production casing, a toughness safety criterion must be set up besides the study of perforation bullet, perforation technology and the material property of production casing. In this article, the stress state of production casing in perforating is analyzed, and the feasibility of A KV /σ Y  as a toughness safety criterion is proven by applying metal dynamic deformation theory and the fracture mechanics theory of thin wall pipe. On the basis of laboratory perforation tests and real bullet perforation tests in simulation well, the correlation criterion between the tendency of perforation cracking and the mechanical properties of casing material is set up, which is A KV /σ Y ≥5.3×10 -2 J/MPa. The influences of some parameters such as the toughness of different grade casing, the dimension and anisotropy of impact sample and testing temperature on the criterion are also discussed.