油层水力压裂是一种有效的增产增注措施。大庆油田广泛采用水力压裂以来,已经取得了显著的效果,对油田高产稳产作出了贡献。关于裂缝形态、延伸范围和裂缝形成原因等一些机理问题,国内外都在进行探讨,采用的研究方法很多。但是在油田上用打检查井钻取岩心的方法来直接观察研究这些问题,在国内尚无先例。一九七七年十一月至一九七八年元月我们在曾经采取过压裂措施的中3—7井和中4—7并近旁分别相距25.02米及24.19米的地方,各钻了一口密闭取心检查井,井号分别为中 Hydraulic fracturing is an effective measure to increase production and increase injection. Since the widespread hydraulic fracturing in Daqing Oilfield, it has achieved remarkable results and contributed to the high and stable oil production. On the fracture shape, extension and crack formation causes some mechanism issues, both at home and abroad are explored, using many research methods. However, there is no precedent in the field to directly observe and study these problems by drilling the core with inspection wells in oil fields. From November 1977 to January 1978, we drilled at wells of Nos. 3-7 and 4-7 and in the vicinity of 25.19 and 24.19 meters, respectively, where fracturing had taken place. A closed coring inspection wells, respectively, pound number