Patent ID: 6039128
Filing Date: 2000-03-21
Classification: E21B

Abstract:
A method of obtaining core samples during the drilling of a well, comprising the steps of:rotating a drill pipe to drill the well;introducing drilling mud into the drill pipe, wherein the drilling mud lifts cuttings produced by a drill bit disposed on an end of the pipe to a surface of the well;introducing a volume of matrix fluid into the drill pipe, the matrix fluid having a colloidal, viscous nature;encapsulating the cuttings and liquid contained in pore spaces and interstices of the cuttings with the matrix fluid to protect the cuttings from the drilling mud;lifting the encapsulated cuttings to the surface of the well, wherein the cuttings are protected by the matrix fluid during the upward movement to preserve the original conditions of the cuttings and the liquid contained in pore spaces and interstices thereof taken at the depth of sampling;wherein the step of introducing a volume of matrix fluid comprises introducing the fluid into the drill pipe at predetermined intervals during drilling, wherein the matrix fluid is pushed downwards towards a bottom of the well by the drilling mud;and further including the step of stopping the rotation of the drill pipe before the step of introducing the matrix fluid and until the matrix fluid reaches the bottom of the well.