Novel Analytical Methods of Temperature Interpretation in Horizontal Wells

Abstract

Long (horizontal) completion intervals typically show a wide variation in the inflow distribution along their length due to either formation heterogeneity or (frictional) flow pressure losses. Monitoring of the inflow profiles in such wells is an important step in efficient reservoir management. Accurate temperature measurements (using distributed temperature sensors, permanent downhole gauges or other forms of production logging) have become more widely available in recent years. Many published papers describe temperature sensing and its phenomenological interpretation; but few attempts have been made recently to develop a comprehensive mathematical basis for the analysis of downhole temperature behaviour.This paper presents a holistic, analytical, mathematical model for calculation of the temperature profile in horizontal wells producing liquids for reservoirs where thermal recovery methods are not being employed. The model presented in this paper rigorously accounts for (1) the Joule-Thomson effect, (2) convection, (3) transient fluid expansion and (4) time-dependent heat loss to the surrounding layers.A synthetic horizontal well model has been built using a commercial, scientific simulator as a test-bed to provide the data to allow a rigorous evaluation of the efficacy of our novel analytical methods. Asymptotic, analytical solutions have also been found for transient and steady-state flow. It has also been found possible, in addition to these constant flow rate solutions, to apply the well known pressure analysis solution techniques for the estimation of (1) thermal properties and (2) inflow profiling.The methods proposed here can be applied to a wide variety of well completion types, flow conditions and system properties. They form the basis for the calculation of oil and water flow phase cuts and distributions based purely on temperature measurements. Their use will further increase the potential applications of the modern downhole monitoring and control capabilities currently being installed in wells. As such, they will form an essential element of the "digital oil field".

Modeling and Analysis of Temperature Transients Caused by Step-Like Change of Downhole Flow Control Device Flow Area

“…Pressure transient analysis in multi-layer scenario has been made but it can not discriminate different zonal pressures (Muradov and Davies 2011). In particular if it is possible to accomplish this without zonal shut-in.…”

“…Using transient temperature and pressure Sui developed a numerical simulator for qualitative analysis of changes in permeability and skinfactor in a multilayered vertical well (Sui, Zhu et al 2008). A basic analysis workflow is available for sandface temperature of a single layer for a horizontal well (Muradov and Davies 2011). Duru has found out that properties such as porosity and saturation could be estimated in an inverse problem from pressure and temperature transient analysis which are not available from conventional pressure transient analysis tools (Duru and Horne 2010).…”

Temperature Prediction Model for a Horizontal Well with Multiple Fractures in a Shale Reservoir

“…Based on this observation, Li and Zhu (2010) presented transient temperature model with transient numerical reservoir model with steady state wellbore model presented by Yoshioka et al This model successfully captured the transient behavior of temperature along the horizontal well for the water coning case and water injection case from the adjacent horizontal well (Li et al, 2011). Muradov and Davies (2011) presented a transient analytical temperature model in a horizontal well with single phase liquid production, but they mainly focused on the temperature change caused by transient behavior of reservoir inflow and did not consider the temperature variation along the horizontal well.…”

Temperature-Prediction Model for a Horizontal Well With Multiple Fractures in a Shale Reservoir

“…Pinzon et al (2007) claimed that the usage of drawdown pressure overestimates the temperature change, and it was consistent with the calculation method presented by Brady et al (1998) who used the half of the drawdown pressure. In the work by Yoshioka et al (2007), they used analytical solution given by the reservoir thermal model for the arriving temperature, and Sui et al (2008a) and Muradov and Davies (2011) also used the analytical solution at the sand face. Li and Zhu (2010) took the analogous approach with the work done by Peaceman (1983) for pressure, and solved simplified 1D ordinary differential equation of reservoir thermal model in the reservoir grid which contains wellbore to compute the arriving temperature.…”