Borehole temperature distribution when drilling fluid loss occurs in the two-dimensional area at the bottom-hole during drilling

Abstract: During the drilling process, the temperature distributions of the borehole and the formation under the condition of drilling fluid loss have a very significant effect on the borehole pressure prediction, the rheological design of drilling fluid and the borehole stability. Aiming at the complex downhole situations as drilling fluid loss occurs during drilling, a new two-dimensional model is proposed to study the temperature distributions of the borehole and the surrounding formation in the presence of the lost circulation. The law of the borehole temperature distribution when drilling fluid loss took place in the two-dimensional area at the bottom of the well was obtained. Comparing with the scenario of no drilling fluid loss, the borehole temperature is reduced at the same well depth in the case of drilling fluid loss. The occurrence of drilling fluid loss greatly disturbs the temperature distribution of drilling fluid in the annulus in the drilling fluid loss area. The location of drilling fluid loss has a conspicuous effect on the borehole temperature distributions. The occurrence of drilling fluid loss renders a more prominent effect of casings on the temperature profile of the medium around the borehole. As the drilling fluid loss rate increases, the borehole temperature at the same well depth decreases.