the narrow operating window between pore pressure and fracture pressure makes drilling difficult in some operations. a feasibility study of managed pressure drilling (mpd) is carried out on iran darquain oil field. the previous wells drilled in this field showed that mud returns were lost during drilling gadvan formation. the present work addresses this problem by means of surface back pressure...

We generalize the so-called “deflected anomaly mediation” scenario to the case where threshold corrections of heavy messengers to the sparticle squared-masses are positive. A concrete model realizing this scenario is also presented. The tachyonic slepton problem can be fixed with only a pair of messengers. The resultant sparticle mass spectrum is quite different from that in the conventional de...

The study of rotary steering drilling technology is currently one of the hot topics in the drilling engineering field. It requires accurate well trajectory control instructions when rotary steerable tools are applied to achieve the well trajectory control goal. A drilling trajectory prediction model will benefit this progress. According to the continuous beam theory, a mechanical model of push-...

Multiplicity of the effective factors in drilling reflects the complexity of the interaction between rock mass and drilling bit, which is followed by the dependence of parameters and non-linear relationships between them. Rock mass or, in other words, the formation intended for drilling, as the drilling environment, plays a very essential role in the drilling speed, depreciation of drilling bit...

Scientific selection of drill bits during drilling is a key technology to achieve high-speed drilling and reduce drilling costs. Based on the analysis of bit’s working principles and its applicable conditions and in accordance with the well conditions of ultra-deep wells in Y area of Tarim Oilfield, this study has conducted mathematical statistics on a large number of actual drilling practices ...