Present Methods of Drilling Process Analysis, Forecasting, and Control in Conditions of Insufficient Information

Abstract

Abstract In many cases the technological processes of drilling wells, especially in exploratory drilling, are carrud out in conditions of insufficient information. Shortage of information is connected with lack of data on geological features of the drilled area, rock physical, mechanical and rheological properties, with complexity and uncertainly of heat-mass exchange processes in the system "well-formation", drill pipes and casing interaction with rocks, bit interaction with boffom hole and so on. Besides, it should be noted, that the driller often deals with misrepresented initial information. It is in these conditions it is nessesary to investigate multicriterion complicated technological process of drilling and provide high effeciency of decisions made in conflict situations. Howether, the experience and intuition do not always provide the best choice in these conditions. The objective can be accomplished only on the base of complex approach to the procedure of making decisions and using the up-to-day methods of investigation of complicated and undefined systems. In the paper, depending on the significance and complexity of the investigated technological process, different methods of making decisions in the conditions of insufficient information are considered. For this, the principles of simulation, methods of indistinct sets, variation principles of mechanics, present achievements of dynamic systems theory are used.