نوع مقاله : مقاله پژوهشی
نویسندگان
1 داشجوی دکتری تخصصی؛ دانشکده مهندسی نفت، دانشگاه صنعتی امیرکبیر، تهران، ایران
2 دانشیار، دانشکده مهندسی نفت، دانشگاه صنعتی امیرکبیر، تهران، ایران
3 دانشجوی دکترای تخصصی، دانشکده مهندسی نفت، دانشگاه صنعتی امیرکبیر، تهران، ایران
4 دانشکده نفت دانشگاه صنعتی امیرکبیر، تهران، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Use of PDC bits in oil industry has been increased in recent years despite the fact that they are more expensive than roller cone bits. Therefore, developing a comprehensive rock-bit interaction model for this type of bits is too important. Previously, several mathematical models have been proposed for modeling rock-bit interaction. Most of these models (e.g. Nishimatsu’s model) do not consider the effects of in-situ stresses at all. Some other models assume that the values of rock failure angle at downhole and ambient conditions are equal. In fact, even though these models use in-situ stresses to calculate the cutting force, they do not consider in-situ stresses in analytical modeling. In this work, an analytical relation for rock failure angle including in-situ stresses is derived. Based on this relation, a novel analytical rock-bit interaction model to predict cutting force is presented. Applying field data on mentioned models results in improving rock failure angle and cutting force calculations for about 15-20%.
کلیدواژهها [English]