Empirical Random Kick Model and Casing Reliability

Beck, André Teófilo; Cecílio, Diogo L.; Gomes, Wellison José de Santana; Tessari, Rodolfo Krul; Jacinto, Carlos Magno Couto

doi:10.2118/201200-pa

Cited by 3 publications

(3 citation statements)

References 21 publications

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“…Briefly, the randomness of these three parameters can be used as the main factors affecting the uncertainty of casing residual strength after wear and tear. Therefore, in terms of the influence of the randomness of parameters on the uncertainty of casing strength after abrasion, the wear depth, formation elastic modulus and formation Poisson's ratio can be regarded as variables, and the other parameters can be regarded as constants [8]. Then Eq.…”

Section: Comparison Of Variation Coefficients Of Casing Strength Para...mentioning

confidence: 99%

“…Let the probability density function of (Ä, À, Z) be f Ä;À;Z ð Þ I n; g; f ð Þ, since Ä, À and Z are independent of each other, it can be attained that [8]:…”

Section: Comparison Of Variation Coefficients Of Casing Strength Para...mentioning

confidence: 99%

“…Therefore, this directly affects casing design strength and safety and reliability of well completion and production. El-Sayed et al [6][7][8] studied the effects of drilling conditions, BHA, hole dogleg degree and drilling fluid performance on casing wear. Based on energy transfer, a casing wear efficiency model is established to predict and analyze the casing wear.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Uncertainty Analysis of the Residual Strength of Non-Uniformly Loaded Casings in Deep Wells

Wang¹,

Zhang²,

Lin³

et al. 2023

Fluid Dynamics &Amp; Materials Processing

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An uncertainty analysis method is proposed for the assessment of the residual strength of a casing subjected to wear and non-uniform load in a deep well. The influence of casing residual stress, out-of-roundness and non-uniform load is considered. The distribution of multi-source parameters related to the residual anti extrusion strength and residual anti internal pressure strength of the casing after wear are determined using the probability theory. Considering the technical casing of X101 well in Xinjiang Oilfield as an example, it is shown that the randomness of casing wear depth, formation elastic modulus and formation Poisson's ratio are the main factors that affect the uncertainty of residual strength. The wider the confidence interval is, the greater the uncertainty range is. Compared with the calculations resulting from the proposed uncertainty analysis method, the residual strength obtained by means of traditional single value calculation method is either larger or smaller, which leads to the conclusion that the residual strength should be considered in terms of a range of probabilities rather than a single value.

show abstract

Section: Comparison Of Variation Coefficients Of Casing Strength Para...mentioning

confidence: 99%

“…Let the probability density function of (Ä, À, Z) be f Ä;À;Z ð Þ I n; g; f ð Þ, since Ä, À and Z are independent of each other, it can be attained that [8]:…”

Section: Comparison Of Variation Coefficients Of Casing Strength Para...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Uncertainty Analysis of the Residual Strength of Non-Uniformly Loaded Casings in Deep Wells

Wang¹,

Zhang²,

Lin³

et al. 2023

Fluid Dynamics &Amp; Materials Processing

View full text Add to dashboard Cite

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An Assessment of the Kick Tolerance Calculation, its Uncertainty and Sensitivity

Thorogood

Robertson

Castillo

et al. 2022

IADC/SPE International Drilling Conference and Exhibition

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Much of the contemporary literature on kick tolerance relates to the practical aspects of the calculation and the effects of the underlying assumptions and necessary simplifications. It tends to a formulaic approach involving unconstrained uncertainties about pore pressure, kick intensity, drilling fluid density safety factors which tend to overlook the inherent complexities of the subsurface environment and the reality of model limitations. The literature on kick tolerance highlighting the strengths, weaknesses and limitations of the classic calculation is reviewed before describing a first-principles approach to determining the consequences which casing seat strength limitations and strength variations in the overall open-hole section imposes on safe well designs as a result of uncertainties in the input variables and basic model assumptions. The classic kick tolerance calculation, together with its associated assumptions, yields only a single value for a given set of inputs. The uncertainties and sensitivities are those introduced by the variables and the choice of operational procedures. The Monte Carlo method is employed to explore the effect of uncertainties in the input parameters and associated assumptions. The analysis is based on the Driller’s Method for kick circulation, with a single bubble insoluble gas with optional allowances for gas gravity and thermal regimes. To examine the various factors influencing kick tolerance, the problem is framed graphically in terms of an allowable influx volume, the dependent variable, against bottom hole pressure, the independent variable, on which pore pressure, its uncertainty, possible variations in shoe strength, strength in the open-hole section, drilling fluid density with associated equivalent circulating density and swab effects can be examined. Application of the new approach demands significant prior work to determine the uncertainties inherent in the problem. Some of these uncertainties, such as drilling fluid density variations, swabbing and equivalent circulating density must be evaluated by the engineer as part of the normal well design. Other factors, such as shoe strength, pore pressure variability and formation depth error bars must be developed as part of a multi-disciplinary effort within the planning team. Often ignored due to the spatial uncertainties, natural fractures intersecting the borehole could be inherently unstable and prone to hydraulic communication between borehole and formation. Synthesising some of these considerations into a simple calculation framework allows the effect of these parameters either individually or collectively to be quantified and provides a view of the potential geological uncertainties inherent in a well design. The approach offers a starting point for thinking about the nature of geological uncertainties and carrying them into drilling programmes

show abstract

An Assessment of the Kick Tolerance Calculation, Its Uncertainty, and Sensitivity

Thorogood¹,

Robertson²,

Castillo

et al. 2022

SPE Drilling &Amp; Completion

View full text Add to dashboard Cite

Summary Much of the contemporary literature on kick tolerance relates to the practical aspects of the calculation and the effects of the underlying assumptions and necessary simplifications. It tends to a formulaic approach involving unconstrained uncertainties about pore pressure, kick intensity, drilling fluid density safety factors which tend to overlook the inherent complexities of the subsurface environment, and the reality of model limitations. The literature on kick tolerance highlighting the strengths, weaknesses, and limitations of the classic calculation is reviewed before describing a first-principles approach to determining the consequences which casing seat strength limitations and strength variations in the overall openhole section impose on safe well designs as a result of uncertainties in the input variables and basic model assumptions. The classic kick tolerance calculation, together with its associated assumptions, yields only a single value for a given set of inputs. The uncertainties and sensitivities are those introduced by the variables and the choice of operational procedures. The Monte Carlo method is used to explore the effect of uncertainties in the input parameters and associated assumptions. The analysis is based on the driller’s method for kick circulation, with a single-bubble insoluble gas with optional allowances for gas gravity and thermal regimes. To examine the various factors influencing kick tolerance, the problem is framed graphically in terms of an allowable influx volume, the dependent variable, against bottomhole pressure (BHP), the independent variable, on which pore pressure, its uncertainty, possible variations in shoe strength, strength in the openhole section, drilling fluid density with associated equivalent circulating density (ECD) and swab effects can be examined. Application of the new approach demands significant prior work to determine the uncertainties inherent in the problem. Some of these uncertainties, such as drilling fluid density variations, swabbing, and ECD, must be evaluated by the engineer as part of the normal well design. Other factors, such as shoe strength, pore pressure variability, and formation depth error bars must be developed as part of a multidisciplinary effort within the planning team. Often ignored due to the spatial uncertainties, natural fractures intersecting the borehole could be inherently unstable and prone to hydraulic communication between borehole and formation. Synthesizing some of these considerations into a simple calculation framework allows the effect of these parameters either individually or collectively to be quantified and provides a view of the potential geological uncertainties inherent in a well design. The approach offers a starting point for thinking about the nature of geological uncertainties and carrying them into drilling programs.

show abstract

Empirical Random Kick Model and Casing Reliability

Cited by 3 publications

References 21 publications

Uncertainty Analysis of the Residual Strength of Non-Uniformly Loaded Casings in Deep Wells

Uncertainty Analysis of the Residual Strength of Non-Uniformly Loaded Casings in Deep Wells

An Assessment of the Kick Tolerance Calculation, its Uncertainty and Sensitivity

An Assessment of the Kick Tolerance Calculation, Its Uncertainty, and Sensitivity

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