Automated Characterization of Drilling Fluid Properties
Automated Characterization of Drilling Fluid Properties

Author: Gregory John Sullivan

Publisher:

Published: 2016

Total Pages: 212

ISBN-13:

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Accurate measurement of drilling fluid properties is essential in order to optimize wellbore construction, and in particular to properly manage hydraulics. It becomes even more crucial during deepwater drilling when a narrow mud window is present which may require the use of more advanced drilling technologies such as Managed Pressure Drilling (MPD) and Dual Gradient Drilling (DGD). Operating these technologies properly requires the use of sophisticated hydraulic models that require accurate rheological information as input. However, a full mud check with determination of all relevant rheological parameters is usually only carried out once per day, and augmented with one or two partial checks in the 24-hour period. Such intermittent and unreliable measurements are unfortunately not sufficient to provide the required inputs for ‘real-time' hydraulic modeling and control. A more practical approach for a continuous, automated monitoring of the drilling fluid properties is therefore called for. The method used here is based on the pipe viscometer approach rather than the traditional rotational viscometer method. In addition to the fluid rheology, important inputs for hydraulic models, such as mud density, transition to turbulent flow (critical Reynolds number), and real-time friction factor for non-Newtonian drilling and completion fluids are also obtained using the pipe viscometer. A prototype of this equipment was constructed, tested, and fully automated at The University of Texas at Austin. The flow loop was tested with several weighted and unweighted mud systems. During the measurement process, the driving pump was ramped up and held intermittently at various flow rates to measure the laminar frictional pressure loss in the pipe section. The data thus obtained was analyzed by software that generated a flow curve and from it derived relevant mud rheological parameters using a suitable rheological model. It also proved possible to extend the test to the turbulent flow regime and obtain the ‘true' friction factor in real-time for each particular fluid, rather than relying on a limited number of correlations that quite often exhibit inaccurate results, particularly for the Yield Power Law (YPL) fluids. Several successful tests with different mud systems indicate the reliability and robustness of the proposed technique.

Investigation on the Effects of Ultra-high Pressure and Temperature on the Rheological Properties of Oil-based Drilling Fluids
Investigation on the Effects of Ultra-high Pressure and Temperature on the Rheological Properties of Oil-based Drilling Fluids

Author: Chijioke Stanley Ibeh

Publisher:

Published: 2010

Total Pages:

ISBN-13:

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Designing a fit-for-purpose drilling fluid for high-pressure, high-temperature (HP/HT) operations is one of the greatest technological challenges facing the oil and gas industry today. Typically, a drilling fluid is subjected to increasing temperature and pressure with depth. While higher temperature decreases the drilling fluid0́9s viscosity due to thermal expansion, increased pressure increases its viscosity by compression. Under these extreme conditions, well control issues become more complicated and can easily be masked by methane and hydrogen sulfide solubility in oil-base fluids frequently used in HP/HT operations. Also current logging tools are at best not reliable since the anticipated bottom-hole temperature is often well above their operating limit. The Literature shows limited experimental data on drilling fluid properties beyond 350°F and 20,000 psig. The practice of extrapolation of fluid properties at some moderate level to extreme-HP/HT (XHP/HT) conditions is obsolete and could result in significant inaccuracies in hydraulics models. This research is focused on developing a methodology for testing drilling fluids at XHP/HT conditions using an automated viscometer. This state-of-the-art viscometer is capable of accurately measuring drilling fluids properties up to 600°F and 40,000 psig. A series of factorial experiments were performed on typical XHP/HT oil-based drilling fluids to investigate their change in rheology at these extreme conditions (200 to 600°F and 15,000 to 40,000 psig). Detailed statistical analyses involving: analysis of variance, hypothesis testing, evaluation of residuals and multiple linear regression are implemented using data from the laboratory experiments. I have developed the FluidStats program as an effective statistical tool for characterizing drilling fluids at XHP/HT conditions using factorial experiments. Results from the experiments show that different drilling fluids disintegrate at different temperatures depending on their composition (i.e. weighting agent, additives, oil/water ratio etc). The combined pressure-temperature effect on viscosity is complex. At high thresholds, the temperature effect is observed to be more dominant while the pressure effect is more pronounced at low temperatures. This research is vital because statistics show that well control incident rates for non- HP/HT wells range between 4% to 5% whereas for HP/HT wells, it is as high as 100% to 200%. It is pertinent to note that over 50% of the world0́9s proven oil and gas reserves lie below 14,000 ft subsea according to the Minerals Management Service (MMS). Thus drilling in HP/HT environment is fast becoming a common place especially in the Gulf of Mexico (GOM) where HP/HT resistant drilling fluids are increasingly being used to ensure safe and successful operations.

Automated Surface Measurements of Non-Newtonian Fluid Properties
Automated Surface Measurements of Non-Newtonian Fluid Properties

Author: Sercan Gul

Publisher:

Published: 2021

Total Pages: 0

ISBN-13:

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Accurate and frequent mud checking is critical to optimum well construction. Proper assessment and management of drilling fluid properties such as density and rheology maintains the fluid in its role as the primary well control barrier and optimizes the fluid 's hydraulics and hole cleaning ability. However, a full mud check while drilling is typically done only once or twice a day. Moreover, the measurements are performed using largely antiquated equipment for which the data quality and reliability are highly dependent on the practicing mud engineer. An automated, continuous, and practical way of measuring and monitoring drilling fluid properties is therefore needed. Novel measurement approaches are introduced to achieve automated surface measurements of non-Newtonian fluid properties. The automated rheology measurements are conducted by a novel helical pipe-viscometer method. The real-time friction factor and critical Reynolds number values are provided by using a straight pipe-viscometer system. Other important fluid properties such as pressurized-density, oil/water ratio and temperature are provided using high-quality in-line sensors. Filtrate loss information is provided by leveraging machine-learning regressions using the automatically measured values of rheological properties, density and electrical stability. Moreover, a novel in-line X-ray fluorescence measurement approach is introduced to determine solids content and salinity of fluids. This dissertation provides details about the measurement technologies as well as the results from laboratory experiments and field trials. It was shown that by combining the measurement systems introduced here, it is possible to construct a skid unit that performs continuous drilling fluid sampling and measurements at variable temperatures. The unit is able to send real-time data to data servers and provide detailed mud reports to engineers working either on-site or remotely. The technology described here opens the door to fully automated fluid monitoring, maintenance, and solids control in well construction operations. This will benefit well construction efficiency (e.g. lowering drilling costs by better cuttings transport), quality, productivity (e.g. reducing reservoir impairment from unwanted solids) and safety (e.g. lowering incidence of well control and lost circulation events due to better equivalent circulating density (ECD) management in narrow margin drilling environments)

Composition and Properties of Drilling and Completion Fluids
Composition and Properties of Drilling and Completion Fluids

Author: HCH Darley

Publisher: Gulf Professional Publishing

Published: 1988-03-22

Total Pages: 658

ISBN-13: 9780872011472

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Composition and Properties of Drilling and Completion Fluids, Fifth Edition, covers the fundamental principles of geology, chemistry, and physics that provide the scientific basis for drilling fluids technology. New material for drilling, logging, and production supervisors and engineers exlains how the choice of a drilling fluid and proper maintenance can profoundly reduce total well costs. It also defines technical terms necessary to the understanding of instructions and information provided by the mud engineer. Updated chapters discuss evaluation of drilling fluid performance, clay mineralogy and colloid chemistry, rheology, filtration properties, hole stability, drilling problems, and completion fluids.

Composition and Properties of Drilling and Completion Fluids
Composition and Properties of Drilling and Completion Fluids

Author: Ryen Caenn

Publisher: Gulf Professional Publishing

Published: 2011-09-29

Total Pages: 721

ISBN-13: 0123838592

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The petroleum industry in general has been dominated by engineers and production specialists. The upstream segment of the industry is dominated by drilling/completion engineers. Usually, neither of those disciplines have a great deal of training in the chemistry aspects of drilling and completing a well prior to its going on production. The chemistry of drilling fluids and completion fluids have a profound effect on the success of a well. For example, historically the drilling fluid costs to drill a well have averaged around 7% of the overall cost of the well, before completion. The successful delivery of up to 100% of that wellbore, in many cases may be attributable to the fluid used. Considered the "bible" of the industry, Composition and Properties of Drilling and Completion Fluids, first written by Walter Rogers in 1948, and updated on a regular basis thereafter, is a key tool to achieving successful delivery of the wellbore. In its Sixth Edition, Composition and Properties of Drilling and Completion Fluids has been updated and revised to incorporate new information on technology, economic, and political issues that have impacted the use of fluids to drill and complete oil and gas wells. With updated content on Completion Fluids and Reservoir Drilling Fluids, Health, Safety & Environment, Drilling Fluid Systems and Products, new fluid systems and additives from both chemical and engineering perspectives, Wellbore Stability, adding the new R&D on water-based muds, and with increased content on Equipment and Procedures for Evaluating Drilling Fluid Performance in light of the advent of digital technology and better manufacturing techniques, Composition and Properties of Drilling and Completion Fluids has been thoroughly updated to meet the drilling and completion engineer's needs. Explains a myriad of new products and fluid systems Cover the newest API/SI standards New R&D on water-based muds New emphases on Health, Safety & Environment New Chapter on waste management and disposal

Rheological Characterization of Complex Drilling Fluid and the Effects on Drilling Hydraulics
Rheological Characterization of Complex Drilling Fluid and the Effects on Drilling Hydraulics

Author: Shiraz Gulraiz

Publisher:

Published: 2021

Total Pages: 0

ISBN-13:

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Pressure management and hole cleaning are fundamental aspects of a successful drilling operation. Despite a plethora of research articles, contradictory results continue to be reported in the literature. The variables involved have been extensively researched but rheology continues to suffer from severe oversimplifications. Few studies go beyond the canonical time-independent characterization and even fewer consider the addition of drill cuttings and thermal effects. The composition of drilling fluids makes them a typical case of complex fluids such that the rheology is dependent on shear rate and flow history. Complex fluids exhibit several peculiar rheological features that are augmented in a drilling environment. The present work investigates the interplay between complex rheology and drilling hydraulics; the latter here refers to bottomhole pressure and cuttings transport. In this work, rheological algorithms are developed to characterize complex rheology. The multiphase mixture of fluid and cuttings is modeled as thixotropic viscoplastic (TVP) suspension. It is observed that high yield stress and flow rate do not guarantee efficient hole cleaning. In most cases, high yield stress deteriorates cuttings transport. A large stress overshoot improves cuttings transport, though the distinction between the static and dynamic yield stresses diminishes as particle concentration increases. Since viscosity lags shear rate changes in thixotropic flows, pressure fluctuates and swirling viscosity profiles are generated, giving rise to localized turbulence and Taylor vortices even at low velocities. Moreover, cuttings transport varies as a power-law function of particle shape, size, and flow rate. Under a geothermal gradient, high-temperature regions develop near the inner pipe as fluid moves upwards. Temperature has a diverse effect on rheology and temperature-viscosity profiles are often non-monotonic. For such fluids, the pressure profile is highly non-linear as most of the frictional losses occur near the bottomhole. Fluids with non-monotonic temperature-viscosity profiles yield better cuttings transport but at the cost of higher pressure. Modeling the time-dependent rheology of drilling fluids while studying drilling hydraulics helps in addressing several contradictions found in the literature. It is recommended that the experimental and computational efforts focused on drilling hydraulics should characterize complex rheology for a better understanding of drilling hydraulics