This paper designs an integrated estimator and L1 adaptive control scheme to address the two main challenges involved in the Managed Pressure Drilling (MPD) system: first, the bottomhole states are updated at a low rate, which can be viewed as unmeasured and thus need to be estimated in real time; and second, the drilling process is subject to uncertainties including unknown parameters (e.g., f...

Information transmission is an important part of the wellbore trajectory automatic control system. Combined with the characteristics of the guided drilling system, drilling fluid pulse is selected as a tool for trajectory control. Negative pulse transmission of drilling fluid is one of the key technologies to realize wellbore trajectory automatic control. In this paper, the working principle of...

PURPOSE Bone drilling is a major part of orthopaedic surgery performed during the internal fixation of fractured bones. At present, information related to drilling force, drilling torque, rate of drill-bit penetration and drill-bit rotational speed is not available to orthopaedic surgeons, clinicians and researchers as bone drilling is performed manually. METHODS This study demonstrates that ...

Laboratory experimental results of waterjet drilling have rarely been scaled up to the field scale. This article presents the scaling criteria for designing waterjet drilling laboratory experiments for simulating a given oilfield operation. Dimensional analysis is used to derive scaling groups for the waterjet drilling technique. The proposed scaling approach meets all important requirements of...

Pressure control drilling technology through the precise control of the entire wellbore annular pressure profile, the bottom of the pressure can always maintain the safety density window, so as to achieve the purpose of safe operation. In the drilling process, the use of conventional drilling technology for drilling operations, easily lead to well, overflow and other drilling accidents. In this...

Friction drilling Process is a rotating conical tool to penetrate the work piece and create a bushing in a single step without generating chips. This work investigates the finite element modeling (FEM) of large plastic strain and high-temperature work-material deformation in friction drilling. The workmaterial deformation is very large, and both the tool and work piece temperatures are high in ...

Environmental concerns surrounding drilling for gas are intense due to expansion of shale gas drilling operations. Controversy surrounding the impact of drilling on air and water quality has pitted industry and lease-holders against individuals and groups concerned with environmental protection and public health. Because animals often are exposed continually to air, soil, and groundwater and ha...