Method of releasing immobilized

Claim 1

IN THE PROCESS OF DRILLING A WELL BOREHOLE IN THE EARTH WHEREIN A DRILL BIT IS ROTATED WITHIN SAID WELL BY A DRILL STRING EQUIPPED WITH DRILL COLLARS, A DRILLING FLUID CONTAINING SOLID MATERIALS IS CIRCULATED WITHIN SAID WELL, A DRILLING FLUID FILTER CAKE FORMS ALONG THE WALL OF SAID WELL BOREHOLE AND, UPON CESSATION OF ROTATION OF SAID DRILL STRING SAID DRILL STRING BECOMES IMMOBILIZED IN SAID FILTER CAKE ALONG SAID WALL OF SAID WELL BOREHOLE BY DIFFERENTIAL PRESSURE STICKING, THE STEPS FOR RELEASING SAID IMMOBILIZED DRILL STRING COMPRISING PASSING INTO SAID WELL BOREHOLE AND INTO CONTACT WITH SAID DRILL STRING AND SAID FILTER CAKE AT THE POINT WHERE SAID DRILL STRING IS IMMOBILIZED A UNITARY BODY OF LIQUID COMPRISING A MIXTURE OF A LIQUID HYDROCARBON AND AN ALKYL ARYL POLYETHYLENE OXIDE HAVING NOT LESS THAN 6 AND NOT MORE THAN 10 CARBON ATOMS IN THE ALKYL GROUP AND ON THE AVERAGE NOT LESS THAN 6 AND NOT MORE THAN 11 ETHYLENE OXIDE GROUPS, MAINTAINING CONTACT OF SAID UNITARY BODY OF LIQUID WITH SAID DRILL STRING AND SAID FILTER CAKE, AND THEREAFTER APPLYING MECHANICAL FORCE TO SAID DRILL STRING TO MOVE SAID DRILL STRING.