INCREASING THE EFFICIENCY OF PNEUMATIC PERCUSSION DRILLING OF HORIZONTAL WELLS

Abstract

The construction of wells in rock masses using the rotary impact method using air hammers is quite common both in Russia and abroad. However, the removal of destroyed rock using the energy of an air jet imposes restrictions on the maximum length of the drilling well, caused by the physical nature of the movement of particles in the airflow. This issue arises especially acutely when constructing horizontal wells. The article considers a method for increasing the efficiency of air percussion drilling of horizontal wells. The features of pneumatic percussion drilling and the scope of its application are noted. The disadvantages of the classical method of drilling with air hammers, associated with pneumatic transportation of the destroyed rock through the annular channel, have been identified. A method has been proposed to increase the efficiency of air percussion drilling by using annular air percussion mechanisms and a double drill string – a drilling method with reverse circulation of a cleaning agent or RC drilling. Unlike the classical method of drilling with air hammers, the efficiency of particle transportation during RC drilling does not decrease as the diameter of the drilled hole increases. It has been shown that pneumatic transportation through a rotating channel makes it possible to remove destroyed rock at lower air flow rates. In addition, through simulation modeling, airflow rates were determined for two systems of transporting destroyed rock with a similar drilling diameter: classical air percussion drilling and reverse circulation drilling. As a result of a comparative analysis of air flow rates, it was found that the air flow speed in a double drill string is more than 2.5 times higher than in classical air percussion drilling, which allows increasing the efficiency and maximum possible length of transportation of destroyed rock.