Patent ID: 9732594
Date: 2017-08-15
CPC Classifications: E21B

Claim:
1. A method of drilling multiple boreholes in a coal bed formation within a single caisson during a drilling phase, wherein one or more of said drilled multiple boreholes are for recovering methane gas from the coal bed formation during a production phase, comprising the following steps: (a) drilling a first vertical borehole from a single location within a single caisson; (b) drilling at least one horizontal well from the first vertical borehole, the horizontal well drilled substantially parallel to a face cleat in the coal bed formation; (c) drilling at least one or more lateral wells from the horizontal well, wherein the said one or more lateral wells are drilled substantially perpendicular to one or more face cleats in the coal bed; (d) continuously circulating drilling fluid during the drilling phase through the drilled first vertical borehole and the said at least one horizontal well and the said one or more lateral wells, said drilling fluid being substantially clear water that will not damage the coal bed formation and said drilling fluid having a hydrostatic pressure and a weight; and (e) applying friction or choke methods or a combination of both said friction and choke methods to the drilling fluid while circulating to increase the hydrostatic pressure of the drilling fluid so as to effectively increase the weight of the drilling fluid so that the hydrostatic pressure of the drilling fluid is at an equilibrium with a hydrostatic pressure in the coal bed formation to prevent collapse during the drilling phase.