APPLICATION OF CASING WHILE DRILLING TECHNOLOGY FOR ACCESSING HYDROCARBON PRODUCING HORIZONS

Applications of the innovative casing while drilling (or drilling while casing) technology for accessing producing horizons of hydrocarbon deposits are analyzed. The technology uses unique drilling rigs and downhole equipment that operates as an integrated drilling system in which standard casing pipes are used to transfer mechanical and hydraulic energy to the bit. The top drive system has recently become the most popular way of drilling oil and gas wells. The top drive systems are a fundamentally new type of drilling rig mechanisms that are designed to perform a whole series of technological operations. The need for downhole operations with the traditionally used drill string is eliminated by using the lower drill string assemblies that are lowered by the cable and connected to the casing string. The casing string can be used as the entire drill string or a part thereof in various ways. Various geological conditions in which this drilling method can be used (on land, on a shelf and under permafrost conditions) are considered, and also the practical experience of applying this technology in fields that differ in climatic and geological conditions is analyzed. The results of these test applications that show the effectiveness of the technology in drilling vertical, directional and horizontal wells are examined as well.