Development and Application of an Underbalanced Drilling Simulator

Bijleveld, A.F.; Koper, M.; Saponja, Jeff

doi:10.2118/39303-ms

Cited by 7 publications

(4 citation statements)

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“…This type of model includes Bijleveld's model (Bijleveld, et al, 1998), Zhou's model (Zhou, 1998) and Perez-Tellez model (Perez-Tellez, et al, 2002). The third type of model predicts more accurately than the first and second types of models and accords with actual field operations.…”

Section: Introductionmentioning

confidence: 91%

Prediction of dynamic wellbore pressure in gasified fluid drilling

2007

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The basis of designing gasified drilling is to understand the behavior of gas/liquid two-phase flow in the wellbore. The equations of mass and momentum conservation and equation of fluid flow in porous media were used to establish a dynamic model to predict wellbore pressure according to the study results of Ansari and Beggs-Brill on gas-liquid two-phase flow. The dynamic model was solved by the finite difference approach combined with the mechanistic steady state model. The mechanistic dynamic model was numerically implemented into a FORTRAN 90 computer program and could simulate the coupled flow of fluid in wellbore and reservoir. The dynamic model revealed the effects of wellhead back pressure and injection rate of gas/liquid on bottomhole pressure. The model was validated against full-scale experimental data, and its 5.0% of average relative error could satisfy the accuracy requirements in engineering design.

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Section: Introductionmentioning

confidence: 91%

Prediction of dynamic wellbore pressure in gasified fluid drilling

2007

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“…Therefore, combining Eqs. 3 and 4, the bubble flow pattern exists in an annulus when 17 (5) in which D ep ‫ס‬D IC + D OT is the equiperiphery diameter.…”

Section: Flow-pattern Prediction Modelsmentioning

confidence: 99%

A New Comprehensive, Mechanistic Model for Underbalanced Drilling Improves Wellbore Pressure Predictions

Pérez-Téllez¹,

Smith

Edwards

2003

SPE Drilling &Amp; Completion

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A new comprehensive, mechanistic model that allows more precise predictions of wellbore pressure and two-phase flow parameters for underbalanced drilling (UBD) is proposed. The model incorporates the effects of fluid properties and pipe sizes and, thus, is largely free of the limitations of empirically based correlations.The model is validated against actual UBD field data and fullscale experiments in which the gas and liquid injection flow rates as well as drilling fluid properties were similar to those used in common UBD operations. Additionally, a comparison against two different commercial, empirically based UBD simulators shows better performance with the mechanistic model. IntroductionIt is generally accepted that the success of UBD operations is dependent on maintaining the wellbore pressure between the boundaries determined by formation pressure, wellbore stability, and the surface equipment's flow capacity. Therefore, the ability to accurately predict wellbore pressure is critically important for both designing the UBD operation and predicting the effect of changes in the actual operation.Because of the complex nature of the hydraulic system of UBD operations in which two or more phases (liquid, gas, and solids) commonly flow, the prediction of pressure drop and flow parameters, such as liquid holdup and in-situ liquid and gas velocities, are performed mainly with empirical, two-phase flow methods. The Beggs and Brill 1 correlation is the most popular among the current, commercial UBD simulators. However, it is recognized by the petroleum industry that most of these empirical correlations were developed from experimental databases, thereby making extrapolation hazardous. 2 Moreover, the Beggs and Brill 1 correlation has been shown to overpredict or fail to predict bottomhole pressures for both vertical and horizontal UBD operations. 3,4 Since the mid-1970s, significant progress has been made in understanding the physics of two-phase flow in pipes and production systems. This progress has resulted in several two-phase flow mechanistic models to simulate pipelines and wells under steadystate as well as transient conditions. Consequently, mechanistic models, rather than empirical correlations, are being used with increasing frequency for designing multiphase production systems. Based on this trend of improvement, the application of mechanistic models to predict wellbore pressure and two-phase flow parameters seems to be the solution to increasing the success of UBD operations by improving such predictions.Literature Review. Bijleveld et al. 5 developed a steady-state UBD program to assist well engineers in planning and executing underbalanced operations. This in-house computer program uses the mechanistic two-phase flow approach. However, there is almost no technical information in the literature about implementing the mechanistic models in UBD operations.Hasan and Kabir 6 developed a mechanistic model to estimate the void fraction during upward concurrent two-phase flow in

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“…When ep D is greater than the right hand side of Equation (5), bubble flow can exist. Therefore, the agglomeration or coalescence of small gas bubbles into large Taylor bubbles, which occurs when the in-situ gas rate increases (void fraction increases), is the basic transition mechanism from bubble to slug flow.…”

Section: Flow Pattern Prediction Modelsmentioning

confidence: 99%

A New Comprehensive, Mechanistic Model for Underbalanced Drilling Improves Wellbore Pressure Predictions

Perez-Tellez¹,

Smith²,

Edwards³

2002

Proceedings of SPE International Petroleum Conference and Exhibition in Mexico

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TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractIt is generally accepted that the success of underbalanced drilling (UBD) operations is dependent on maintaining the wellbore pressure between boundaries determined by the formation pressure, wellbore stability, and the flow capacity of the surface equipment. Therefore, the ability to accurately predict wellbore pressure is critically important for both designing the UBD operation and predicting the effect of changes in the actual operation. Most of the pressure prediction approaches used in current practice for UBD are based on empirical correlations, which frequently fail to accurately predict the wellbore pressure. Consequently, the current trend is toward increasing use of prediction methods based on phenomenological or mechanistic models. This paper presents an improved, comprehensive, mechanistic model for pressure predictions throughout a well during UBD operations. The comprehensive model is composed of a set of state-of-the-art mechanistic steady-state models for predicting flow patterns and calculating pressure and two-phase flow parameters in bubble, dispersed bubble, and slug flow. In contrast to other mechanistic methods developed for UBD operations, the present model takes into account the entire flowpath including downward two-phase flow through the drill string, two-phase flow through the bit nozzles, and upward two-phase flow through the annulus. Additionally, more rigorous, analytical modifications to the previous mechanistic models for UBD give improved wellbore pressure predictions for steady state flow conditions. The results of using the new, comprehensive model were validated against two real wellbore configurations with different flow areas. Field data from a Mexican well, drilled with the simultaneous injection of nitrogen and a non-Newtonian fluid and full-scale experimental data from the literature validate the improved model predictions. Additionally, a comparison of the model results against two commercial UBD simulators, which rely on empirical correlations, confirm the expectation that mechanistic models perform better in predicting two phase flow parameters in UBD operations.

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Development and Application of an Underbalanced Drilling Simulator

Cited by 7 publications

References 0 publications

Prediction of dynamic wellbore pressure in gasified fluid drilling

Prediction of dynamic wellbore pressure in gasified fluid drilling

A New Comprehensive, Mechanistic Model for Underbalanced Drilling Improves Wellbore Pressure Predictions

A New Comprehensive, Mechanistic Model for Underbalanced Drilling Improves Wellbore Pressure Predictions

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