摘要 |
<p>In a well drilling operation (10), drilling fluid (70) is used to remove rock cuttings (68) and associated formation fluids released by the drill bit (84) and transport them to the surface. At the surface, a portion of these cuttings and fluids is extracted from the drilling fluid (70) for analyses. The resulting data are used in formation evaluation. This method shows how to determine the concentrations of specific formation fluids in the drilling fluid by adding and maintaining select foreign substance of controlled concentration to the drilling fluid as a reference fluid (64), and factoring the returned formation fluids by the reference fluid. The method also shows how the technique is used as a means to assure quality control of the measuring system and as a non-disruptive means to measure lag.</p> |