This paper presents an integrated adaptive estimator-controller scheme for a class of systems with only partially measured states. To estimate the non-measured states, a fast adaptive estimator is applied. The estimation is used in the L1 adaptive controller, which adapts to time-varying unknown parameters and time-varying bounded disturbances in the system without restricting their rate of var...

A system that applies a method of knowledge-intensive case-based reasoning, for repair and prevention of unwanted events in the domain of offshore oil well drilling, has been developed in cooperation with an oil company. From several reoccurring problems during oil well drilling the problem of ”lost circulation”, i.e. loss of circulating drilling fluid into the geological formation, was picked ...

In this paper the effect of dynamic wavelength allocation (DWA) scheme implementation to the OBS node performance is investigated. We have developed the mathematical model of an OBS node in order to evaluate the burst blocking probability. It is proposed to allocate a part of total wavelength capacity to be used by deflected bursts only. The results obtained from the model show that if the numb...

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...

This overview of different applications of CBR in petroleum engineering is based on a survey and comparative evaluation of different successful applications of CBR. The number of papers and research groups is indicative of importance, need, and growth of CBR in different industries. Applicationoriented research in the area of case based reasoning has moved mature research results into practical...

Optimization of drilling fluid parameters such as mud weight, salt concentration, and temperature is essential to alleviate instability problems during drilling through shale sections. The selection of suitable mud parameters can benefit from analyses that consider significant instability processes involved in shale-drilling–fluid interactions. This paper describes the development of analytical...

A mathematical model has been developed to predict the temperature distribution in wellbores either offshore or inshore. It is incorporated the different activities encountered during drilling operations. Furthermore, the effect of drill collar and casings and bit rotating in a well during completion has been considered. The two dimensional approach is presented in the form of a computer progra...