DETERMINING FORMATION GAS COMPOSITION DURING WELL DRILLING

摘要

Some aspects determining formation gas composition during well drilling can be implemented as a computer-implemented method, a computer-readable medium, or a computer system. A theoretical diffusion coefficient for a drilling fluid that comprises gas from a formation through which the drilling fluid is flowed is determined. The theoretical diffusion coefficient is based on an extraction of all of the gas from the drilling fluid. An experimental diffusion coefficient for the drilling fluid based on well drilling parameters is determined. A concentration of the gas at the formation is determined based, at least in part, on a difference between the theoretical diffusion coefficient and the experimental diffusion coefficient. The determined concentration at the formation is provided.