mohammadhadi parhamvand - science and researh branch islamic azadi university
ehsan momeni - science and researh branch islamic azadi university

the collapse of casing and tubing may lead to the loss of a well . Studies on this issue have been of great interest to the oil industry . At present , we have the technology and systems that can identify the most relevant contributing factors to this phenomenon , which permits development of preventive measures that will save significant economic resources. collapse is a complex phenomenon with a great many factors and parameters that influence its effect. the collapse phenomenon is commonly attributed to suspected quality problems in the pipe. however , studies show there are a set of causative factors, such as : wear on casing wear due to buckling increased external pressure due to temperature improper depressurization geostatic loads overburden due to plastic formations and tectonic activity . we can predict some of these factors and do preventive methods to reduce costs of collapse but some are not predictable and have huge costs to surmount them like what happened in dangan field because of unreliability of well stiuation.

collapse , casing , tubing , tectonic activity.