Modelling flow for finite conductivity in long horizontal oil wells

Adesina Fadairo,Rasouli Vamegh,Ayokunle Ayinde,George N Iwenjora,Ling Kegang,Olusegun Tomomewo

doi:10.1177/0144598721998497

Adesina Fadairo, Rasouli Vamegh + Show 4 more

Open Access

https://doi.org/10.1177/0144598721998497

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Abstract

The impact of neglected well bore pressure losses due to fluid accumulation and kinetic energy in the fundamental energy equation used for derivation of flowing bottom-hole pressure in horizontal well have been conceived to be a considerable reason for the discrepancy between computed rates from the existing models and actual rates got from production tests. In the study, a new model that investigate all possible well bore pressure losses effect on the production rate of a horizontal oil well have been established. The newly developed model has been validated using the field data obtained from the literature and outcome got from the new model yields more satisfactory results. A more realistic results that evident all flow phenomena in petroleum production well include the initial unsteady, pseudo-steady and steady state flow condition hence flow rate at any given production time has been established for flow of oil along horizontal production well. The concept is useful to estimate flowing bottom-hole pressure and analyze its effect on production rate value of a horizontal oil well without ignoring any pressure resisting terms in the governing thermodynamic equation. The unsteadiness fluid flow period that generally observed after shut in a well have also been demonstrated. Closer agreement between the results obtained using the newly developed model and real life field measurement was observed when compared with the previous model in the literature. The study gives reservoir engineer an exact and helpful device for estimating and assessing horizontal oil well production rate.

Highlights

Horizontal well productivity has become more prominent to meet the demand for global energy resources than vertical wells, this is due to ability to be in contact with more territory in the reservoir, tending to recover higher volumes of hydrocarbons
It is generally recognized that most horizontal wells do not produce at expected production rate which is basically linked to excessive restriction forces experienced in a long horizontal section of the well (Guo et al, 2007; Fadairo et al, 2011) This restriction forces generate large discrepancy between the production rate obtained from various available models and that obtained from the real time gauge measurement
The huge variance was mainly due to the fact that the available flow equations for a drain hole developed by past researchers have been attributed to various assumption in the fundamental govern equation used for their derivation

Summary

Introduction

Horizontal well productivity has become more prominent to meet the demand for global energy resources than vertical wells, this is due to ability to be in contact with more territory in the reservoir, tending to recover higher volumes of hydrocarbons. The early part of the studies that published in the open literature includes stabilized inflow models including both steady state and pseudo-steady state (Giger, 1985; Joshi, 1988), transient flow models (Kuchuk et al, 1991; Ozkan et al, 1989), and gas and water coning behavior (Geiger, 1989; Goode and Kuchuk, 1991), and reservoir simulation concepts of using horizontal wells (Economides et al, 1991) These methods have provided insight into the performance of horizontal wells, they were generally based on a common assumption of the well-being a line sink with a uniform influx boundary condition at the wellbore (Fadairo et al, 2019, 2020a; Kamkom and Zhu, 2005). Assuming the critical Reynold number is 2000, an expression for critical flow rate is obtained as (Guo et al, 2007)

Pr À Pwh b

Results analysis

Conclusion

Limitation