Temperature Prediction for Deepwater Wells: A Field Validated Methodology

Abstract

Abstract A precise knowledge of downhole circulating temperature is necessary for the design of safe well construction operations. The reliability of existing correlation and models is sometimes reduced in deepwater wells. Indeed, the mechanism of heat exchange with the sea is more complex than for rock formation, requiring additional inputs such as sea current, riser geometry and insulation. This paper describes an advanced numerical simulator for the design and evaluation of downhole circulating temperatures during drilling and cementing operations in deepwater wells. The equations governing heat transfer between the wellbore and the sea are developed first. Several methods for obtaining offshore temperature measurement are presented and recommendations are given to use measurement while drilling (MWD) data as part of the design and evaluation process for wellbore temperature. A field case is then presented to illustrate how such MWD data can provide meaningful information for determining circulating and static temperature on deepwater wells. The down-hole measurements were compared to simulated temperature to illustrate how the MWD temperature can be correlated to bottom-hole circulating temperature. Finally, a methodology is proposed to assess the effect of deep water on circulating temperature and cement design based on MWD temperature measurements. P. 339