Patent ID: 8590637
Filing Date: 2013-11-26
Classification: E21B

Abstract:
1. An apparatus for jetting lateral boreholes in a formation from a main wellbore using a high pressure jetting hose conveyed down the wellbore by tubing, the jetting hose supplied with pressurized jetting fluid through the tubing; a speed control sub connected between at least a portion of the tubing and the jetting hose, the speed control sub comprising a jetting fluid path for passing the pressurized jetting fluid from the tubing portion to the jetting hose; wherein the speed control sub is configured to maintain the pressure of the jetting fluid flowing to the speed control sub at a predetermined level when a force between the speed control sub and the jetting hose is at a first predetermined level and to change the pressure of the jetting fluid flowing to the speed control sub from the predetermined level when the force between the speed control sub and the jetting hose increases from the first predetermined level; whereby the speed control sub is responsive to a higher feed-in rate of the tubing down the wellbore relative to a thrust-determined jetting rate of the hose through the formation to cause a noticeable pressure change in the pressurized jetting fluid to an operator.