Research on Wellbore Temperature Field
in Deep-Water CML Dual Gradient Drilling
Geng Zhang 1 , Jun Li 1(B) , Liu Gonghui 1,2 , Yang Hongwei 1 , and Wang Jiangshuai 1
1 College of Petroleum Engineering,
China University of Petroleum (Beijing), Beijing 102249, China
lijun446@vip.163.com
2 Beijing University of Technology, Beijing 100124, China
Abstract. In order to study the distribution law of temperature in deep water
CML dual-gradient drilling wellbore, the coupling relationship between wellbore
temperature, pressure, drilling fluid density and rheological properties was comprehensively considered, and the transient heat transfer model of deep water CML
dual-gradient drilling wellbore was established in combination with the characteristics of deep-water CML dual-gradient drilling process and the law of energy
conservation. Based on an example well, the effects of cycle time and drilling
fluid physical parameters on annulus temperature were analyzed and compared
with conventional drilling. The results show that the annulus temperature in the
lower part of the wellbore decreases and the annulus temperature in the upper
part increases with the increase of the cycle time and the density, specific heat
and consistency coefficient of the drilling fluid. With the increase of thermal conductivity of drilling fluid, the annulus temperature in the lower part of wellbore
increases gradually, while the annulus temperature in the upper part decreases
gradually. Compared with the wellbore temperature of conventional drilling, the
overall wellbore temperature of CML drilling is about 3 °C lowers on average,
and the temperature difference near the mud line can reach about 8 °C.
Keywords: CML dual gradient drilling · Wellbore temperature · Transient heat
transfer model · Temperature pressure coupling
1 Introduction
With the increasing demand for oil and gas resources in China, the center of gravity of
oil and gas exploration and development has gradually shifted to deep and deep water,
and the deep-sea area has become an important substitute area for oil and gas exploration
and development in China. However, there are some problems in deep-water drilling,
such as narrow safety density window and difficult control of wellbore pressure. At the
same time, in the process of drilling, it is easy to occur overflow, leakage, leakage and
co-existence and other downhole complications, which bring great challenges to safe
and efficient drilling [1–3]. In recent years, a new dual-gradient drilling technology for
Controlled Mud Level (CML) has been developed.
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
S. N. Atluri and I. Vušanovi´ c (Eds.): ICCES 2020, MMS 97, pp. 212–223, 2021.
https://doi.org/10.1007/978-3-030-64690-5_20
in Deep-Water CML Dual Gradient Drilling
Geng Zhang 1 , Jun Li 1(B) , Liu Gonghui 1,2 , Yang Hongwei 1 , and Wang Jiangshuai 1
1 College of Petroleum Engineering,
China University of Petroleum (Beijing), Beijing 102249, China
lijun446@vip.163.com
2 Beijing University of Technology, Beijing 100124, China
Abstract. In order to study the distribution law of temperature in deep water
CML dual-gradient drilling wellbore, the coupling relationship between wellbore
temperature, pressure, drilling fluid density and rheological properties was comprehensively considered, and the transient heat transfer model of deep water CML
dual-gradient drilling wellbore was established in combination with the characteristics of deep-water CML dual-gradient drilling process and the law of energy
conservation. Based on an example well, the effects of cycle time and drilling
fluid physical parameters on annulus temperature were analyzed and compared
with conventional drilling. The results show that the annulus temperature in the
lower part of the wellbore decreases and the annulus temperature in the upper
part increases with the increase of the cycle time and the density, specific heat
and consistency coefficient of the drilling fluid. With the increase of thermal conductivity of drilling fluid, the annulus temperature in the lower part of wellbore
increases gradually, while the annulus temperature in the upper part decreases
gradually. Compared with the wellbore temperature of conventional drilling, the
overall wellbore temperature of CML drilling is about 3 °C lowers on average,
and the temperature difference near the mud line can reach about 8 °C.
Keywords: CML dual gradient drilling · Wellbore temperature · Transient heat
transfer model · Temperature pressure coupling
1 Introduction
With the increasing demand for oil and gas resources in China, the center of gravity of
oil and gas exploration and development has gradually shifted to deep and deep water,
and the deep-sea area has become an important substitute area for oil and gas exploration
and development in China. However, there are some problems in deep-water drilling,
such as narrow safety density window and difficult control of wellbore pressure. At the
same time, in the process of drilling, it is easy to occur overflow, leakage, leakage and
co-existence and other downhole complications, which bring great challenges to safe
and efficient drilling [1–3]. In recent years, a new dual-gradient drilling technology for
Controlled Mud Level (CML) has been developed.
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
S. N. Atluri and I. Vušanovi´ c (Eds.): ICCES 2020, MMS 97, pp. 212–223, 2021.
https://doi.org/10.1007/978-3-030-64690-5_20