Experimental Gas Absorption in Petroleum Fluids at HPHT Conditions

Flatabø, Gudny Øyre; Torsvik, Anja; Oltedal, Velaug Myrseth; Bjørkvik, Bård J.A.; Grimstad, Alv-Arne; Linga, Harald

doi:10.2118/173865-ms

Cited by 16 publications

(5 citation statements)

References 6 publications

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“…The experimental setup employed in this work was also described by Flatabø et al (2015). It involves the use of three HPHT piston cylinders with an operating pressure up to 1000 bar and a temperature range from 20°C to 200°C.…”

Section: Experimental Setup and Methodsmentioning

confidence: 99%

Impact on Oil-Based Drilling Fluid Properties from Gas Influx at HPHT Conditions

Torsvik

Skogestad

Linga

2016

IADC/SPE Drilling Conference and Exhibition

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Oil field exploration in extreme areas represents additional requirements to drilling fluid performance and hydraulic models for well control. In general, there is little knowledge about the drilling fluid properties at high pressure, high temperature (HPHT) conditions, and kick models are based on extrapolation of fluid properties from moderate pressures and temperatures. In order to verify the validity of extrapolation to downhole HPHT conditions, increased knowledge about the rheology of drilling fluids under these conditions is required. In this work we have experimentally determined the effect of gas absorption on saturation pressure, density and viscosity at temperatures up to 200°C and 1000 bar. Results have been used to validate computational predictions.We have developed an experimental setup for studying the effects of natural gas dissolved in petroleum fluids under conditions appropriate for drilling operations. The equipment comprises a sample cylinder in which drilling fluid and gas initially can be mixed at exact mass fractions, and the saturation pressure can be determined at the desired temperature. The gas loaded drilling fluid is transferred to a rheometer with a 1000 bar pressure cell and to a high pressure densitometer for viscosity and density measurements, respectively. Density predictions based on well-known models using commercial software have been compared with the experimentally determined fluid densities.In this study we provide accurate measurements of methane solubility in two oil-based drilling fluids (OBDF), which both have the same composition except for the type of base oil. One is based on a refined normal mineral oil and the other is based on a linear paraffin. For various CH 4 /OBDF combinations, density and viscosity are measured at pressures and temperatures ranging from standard conditions to HPHT. The two OBDFs reveal similar flow behaviour, but the one based on a linear paraffin oil has a stronger gel structure and a stronger shear-thinning effect. This fluid is also able to absorb more gas at lower pressure than the fluid with a normal mineral oil. It is shown that the experimental results form an important basis for tuning the software model to fit thermodynamic properties of gas loaded drilling fluid at HPHT conditions. Well operation safety is the main concern at any oil field. Efficient and safe well operations depend on proper knowledge about the behaviour of gas influx in petroleum fluids and the impact of relevant temperature and pressure changes in the well. A major weakness in current models of kick detection is the lack of experimentally verified data for fluid properties at HPHT conditions. Drilling fluids are commonly analysed according to international standards, describing atmospheric conditions and only a few selected temperatures. The data from this study will be analysed and used to validate extrapolations used in computational models. Improved understanding of the two phase gas-drilling fluid flow in the well allows better prediction of gas absorption a...

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Section: Experimental Setup and Methodsmentioning

confidence: 99%

Impact on Oil-Based Drilling Fluid Properties from Gas Influx at HPHT Conditions

Torsvik

Skogestad

Linga

2016

IADC/SPE Drilling Conference and Exhibition

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“…The experimental setup used to measure the barite sag at downhole pressure and temperature conditions is described by Flatabø et al [18]. The setup uses stainless steel piston cylinders with operating pressure up to 1000 bar and a temperature range from 20 to 200 °C.…”

Section: Experimental Setup For Barite Sag Test Cell At Hpht Conditionsmentioning

confidence: 99%

Rheology assessment and barite sag in a typical North Sea oil-based drilling fluid at HPHT conditions

Ofei

N’gouamba

Opedal

et al. 2023

Korea-Aust. Rheol. J.

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The occurrence of barite sag in drilling fluids has relatively often been the cause for gas kicks in oilwell drilling. The subsequent absorption of gas into drilling fluid could lower the density and reduce the viscosity of the drilling fluid, thereby aggravating both pressure control and hole cleaning. In this paper, we present experimental measurements of rheological properties and barite sag in a typical North Sea oil-based drilling fluid at downhole pressure and temperature conditions. A new experimental apparatus was setup for barite sag measurements at static condition with operational temperature and pressure capabilities up to 200 °C (392°F) and 1000 bar (14,503.8 psi), respectively. Rheometry measurements were conducted on fluid samples with and without barite particles at operating conditions up to 90 °C and 100 bar. We observed that at a typical shear rate of 250 s−1, which is experienced in 8.5″ hole annulus, the viscosity of fluid sample with barite increased nearly three times as that of the fluid sample without barite as the temperature and pressure increased. However, temperature effect on viscosity dominates at high shear rates compared to pressure effect. Furthermore, the fluid samples showed more shear-thinning effect with increasing yield stress as the temperature increased. On the other hand, barite sag measurements revealed that whereas fluid samples under high pressure are less prone to sag, high temperature fluid samples, however, promote sag significantly. The data from this study are useful to validate extrapolations used in computational models and to improve understanding and operational safety of sag phenomena at downhole conditions. We also discuss the importance of this study in optimizing drilling operations.

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“…With various non-aqueous fluids being used in drilling operations, the solubility under operating conditions is important to understand the interaction between formation gas and drilling fluids. Flatabø et al (2015) performed extensive experimental work on determining the solubility of methane in two different base oil at high pressure (600 bar) and temperature (20-196 0 C).…”

Section: Literature Reviewmentioning

confidence: 99%

Determination of Absorption Mass Transfer Coefficients of Methane into Drilling Fluid Base Oils

Perry

Mahmud

Chen

2022

Preprint

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Absorption mass transfer coefficients (k_l a) of methane into two widely used drilling fluids base oils-internal olefins and diesel were determined. A laboratory-scale bubble column (0.0254m diameter and 0.71m static liquid height) was used to perform the experiments. Ranges of superficial gas velocity (0.0045-0.0491 m/s) and system pressure (100-300 psig) were covered. Based on the results, the effects of the varying parameters on k_l a have been discussed. Based on the observations, an empirical model for volumetric mass transfer coefficient as a function of superficial gas velocity and gas density was developed. This correlation fitted well (R² >0.98) with the measured k_L a values for the investigated range of operating conditions. This study gives new quantitative insights into the absorption kinetics of methane into two drilling fluid base oils, which are important for improving gas influx management with non-aqueous drilling fluids.

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Experimental Gas Absorption in Petroleum Fluids at HPHT Conditions

Cited by 16 publications

References 6 publications

Impact on Oil-Based Drilling Fluid Properties from Gas Influx at HPHT Conditions

Impact on Oil-Based Drilling Fluid Properties from Gas Influx at HPHT Conditions

Rheology assessment and barite sag in a typical North Sea oil-based drilling fluid at HPHT conditions

Determination of Absorption Mass Transfer Coefficients of Methane into Drilling Fluid Base Oils

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