Development of a Novel Hybrid-Type Rotary Steerable System for Directional Drilling
Unlike conventional resources, unconventional resources, such as shale gas and coal bed methane, are situated horizontally under geological formations. To exploit these resources, directional drilling and hydraulic fracturing technologies are required. In directional drilling, the dog leg severity (DLS), which indicates how much the angle changes while drilling 100 ft, is a major issue with respect to the cost and time of drilling. In this paper, we briefly review different types of directional drilling methods and propose a new hybrid-type rotary steerable system (RSS). DLS calculations based on three-point geometry for these systems are suggested. This hybrid RSS combining two conventional types of RSSs: point-the-bit and push-the-bit systems, achieves better steerability. The hybrid mechanism is implemented using hybrid pads with hydraulic cylinders and a spherical joint. The advantages of the proposed system are demonstrated by performing small-scale prototype and cement block drilling tests.
PDC Bit Steerability Modeling and Testing for Push-the-bit and Point-the-bit RSS
This paper was prepared for presentation at the 2012 IADC/SPE Drilling Conference and Exhibition held in San Diego, California, USA, 6–8 March 2012. This paper was selected for presentation by an IADC/SPE program committee following review of information contained in an abstract submitted by the author(s).
Basic Legal Issues of the Management of Natural Resources of the Caspian Sea
Taking into account different interpretations of legal status of the Caspian Sea, the paper focuses on the current and future legal regime of its natural resources. The relevant international instruments are considered and in this context national approaches of the Caspian states to resource management are legally assessed. In conclusion, some basic prerequisites for the developing scope of the legal regime of the Caspian natural resources are suggested.