The Analysis of Transient Temperature in the Wellbore of a Deep Shale Gas Horizontal Well

• Published in: Processes Vol. 12; no. 7; p. 1402
• Main Authors: Zhang, Shilong, Fu, Jianhong, Peng, Chi, Su, Yu, Zhang, Honglin, Yang, Mou
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.07.2024
• Subjects: Analysis; Bottom hole assemblies; Convection; Deepwater drilling; Density; Drill bits; Drill pipe; Drilling; Drilling and boring; Drilling fluids; Energy conservation; Error analysis; Flow velocity; Fluid flow; Friction; Heat transfer; Horizontal wells; Horsepower; Inlet temperature; Mathematical models; Numerical analysis; Phase transitions; Root-mean-square errors; Shale; Shale gas; Shale oils; South China Sea; Temperature; Temperature distribution; South China Sea
• ISSN: 2227-9717; 2227-9717
• DOI: 10.3390/pr12071402

The transient temperature of the wellbore plays an important role in the selection of downhole tools during the drilling of deep shale gas horizontal wells. This study established a transient temperature field model of horizontal wells based on the convection heat transfer between wellbore and formation and the principle of energy conservation. The model verification shows that the root mean squared error (RMSE) between the measured annular temperature neat bit and the predicted value is 0.54 °C, indicating high accuracy. A well in Chongqing, China, is taken as an example to study the effects of bottom hole assembly (BHA), drill pipe size, drilling fluid density, flow rate, inlet temperature of drilling fluid, and drilling fluid circulation time on the temperature distribution in wellbore annulus. It is found that the increase in annular temperature is about 1 °C/100 m in the horizontal section when a positive displacement motor (PDM) is used. A Φ139.7 mm drill pipe is more favorable for cooling than Φ139.7 mm + Φ127 mm drill pipe. Reducing drilling fluid density and flow rate and inlet temperature is beneficial to reduce bottom hole temperature. Bit-breaking rock, bit hydraulic horsepower, and drill pipe rotation will increase the bottom hole temperature. The research results can provide theoretical guidance for temperature prediction, selection of proper drill tools, and adjustment of relevant parameters in deep shale gas horizontal wells.