The invention discloses a method for judging a
fluid type of a reservoir by utilizing
logging data of while-drilling
drilling fluid, which comprises the following steps of: A, data collection, i.e., collecting performance parameters of the while-drilling
drilling fluid of a target stratum, wherein the performance parameters comprise electrical
conductivity, a temperature, drilling time and a
hydrocarbon component of the
drilling fluid; B,
data processing; C, setting of a crossplot graph data track, i.e., for a plumb shaft, respectively combining an Sf data track and a Tf data track to form an S-T data track, combining the Sf data track and a DHf data track to form an S-DH data track and respectively making crossplots; D, judgment of the
fluid type, i.e., using the S-T dat track for judging a dry layer (a micro gas-bearing
bed) and an aqueous layer, using the S-DH data track for the plumb shaft to judge the gas-bearing
bed or a gas reservoir and using a DO-DH data track for judging an oil-bearing formation or the gas-bearing
bed. When the method is adopted, an explanation result of the method is objective and accurate, the
coincidence rate of the explanation result and the oil testing conclusion is high, and the requirements on production and research can be met.