On the Importance of the Coupling Between Transient Mechanical, Hydraulic and Thermal Effects for the Modelling of Real-Time Drilling Operations

2019 ◽  
Author(s):  
Erik Wolden Dvergsnes ◽  
Eric Cayeux
Keyword(s):  
Real Time ◽  
Drilling Fluid ◽  
Mass Density ◽  
Thermal Conditions ◽  
Time Discretization ◽  
Drill String ◽  
Drilling Process ◽  
Drilling Operation ◽  
Improved Performance ◽  
Transient Models

Abstract Because of the increased importance for the drilling industry to deliver drilling automation solutions, model-based applications for the analysis and control of the drilling process, have become an attractive approach towards improved performance and increased safety. A critical characteristic for such applications is its ability to perform accurate simulations of the drilling operation in real-time, based on a detailed description of the wellbore. In a real-time context, the boundary conditions of the drilling system are seldom constant, therefore reinforcing the importance of utilizing transient models of the drilling process instead of steady state ones. Typical domains that require modelling are related to the mechanical, hydraulic and heat transfer aspects of a drilling operation. The time constants of the force-, momentum-, mass- and energy-conservation equations are sufficiently different to allow for solving each of these equations with different time discretization schemes. Yet, side effects influence the results from each other’s and therefore a time coupling shall nevertheless be accounted for. For instance, for a drilling operation conducted on a floater, the heave induced movement at the top of the string propagates along the drill-string, therefore causing a displacement that induces swab and surge pressure variations, which themselves generate counter-acting forces on the drill-string. In such conditions, both the mechanical and hydraulic frictions generate heat that changes the in situ thermal conditions and therefore the drilling fluid mass density and its rheological behavior. Consequently, heat exchange caused by the drill-string and fluid movements also influences the hydraulic response of the system. Furthermore, thermal expansion will also apply to the drill-string. In this paper, we discuss recent advances related to the coupling between transient mechanical, hydraulic and thermal models, where a key criterion is that the combined drilling model shall be capable of running in real-time on a standard computer. Incorporating these transient models is considered a necessary step towards improved accuracy of simulations, especially on floaters, where heave effects become important. We illustrate various effects by presenting and discussing several simulations results in detail.

Case Studies for the Successful Deployment of Wells Augmented Stuck Pipe Indicator in Wells Real Time Centre

2021 ◽  
Author(s):  
Meor M. Meor Hashim ◽  
M. Hazwan Yusoff ◽  
M. Faris Arriffin ◽  
Azlan Mohamad ◽  
Tengku Ezharuddin Tengku Bidin ◽  
...  
Keyword(s):  
Real Time ◽  
Case Studies ◽  
Drilling Fluid ◽  
Drill String ◽  
Drilling Operation ◽  
Cost Impact ◽  
Drilling Parameters ◽  
The Impact ◽  
Productive Time ◽  
Specific Challenge

Abstract The restriction or inability of the drill string to reciprocate or rotate while in the borehole is commonly known as a stuck pipe. This event is typically accompanied by constraints in drilling fluid flow, except for differential sticking. The stuck pipe can manifest based on three different mechanisms, i.e. pack-off, differential sticking, and wellbore geometry. Despite its infrequent occurrence, non-productive time (NPT) events have a massive cost impact. Nevertheless, stuck pipe incidents can be evaded with proper identification of its unique symptoms which allows an early intervention and remediation action. Over the decades, multiple analytical studies have been attempted to predict stuck pipe occurrences. The latest venture into this drilling operational challenge now utilizes Machine Learning (ML) algorithms in forecasting stuck pipe risk. An ML solution namely, Wells Augmented Stuck Pipe Indicator (WASP), is developed to tackle this specific challenge. The solution leverages on real-time drilling database and supplementary engineering design information to estimate proxy drilling parameters which provide active and impartial pattern recognition of prospective stuck pipe events. The solution is built to assist Wells Real Time Centre (WRTC) personnel in proactively providing a holistic perspective in anticipating potential anomalies and recommending remedial countermeasures before incidents happen. Several case studies are outlined to exhibit the impact of WASP in real-time drilling operation monitoring and intervention where WASP is capable to identify stuck pipe symptoms a few hours earlier and provide warnings for stuck pipe avoidance. The presented case studies were run on various live wells where restrictions are predicted stands ahead of the incidents. Warnings and alarms were generated, allowing further analysis by the personnel to verify and assess the situation before delivering a precautionary procedure to the rig site. The implementation of the WASP will reduce analysis time and provide timely prescriptive action in the proactive real-time drilling operation monitoring and intervention hub, subsequently creating value through cost containment and operational efficiency.

Vibratory Power Losses and Delivery to Rock During Rotary-Vibratory Drilling: Part I: Theory

1980 ◽  
Vol 102 (1) ◽  
pp. 102-109
Author(s):  
D. C. Ohanehi ◽  
L. D. Mitchell
Keyword(s):  
Dynamic Response ◽  
Theoretical Basis ◽  
Drilling Fluid ◽  
Blast Hole ◽  
Drill String ◽  
Power Delivery ◽  
Drilling Process ◽  
Power Losses ◽  
Rotary Drilling ◽  
Drilling Unit

This paper explores a possible theoretical basis for the failure of attempts to develop rotary-vibratory drilling units. With the critical needs in geothermal blast hole excavation and oil exploration, this nation cannot overlook the possibility of accelerating the drilling process by factors of 2 to 20 over the conventional rotary drilling rates. This paper develops the theory for the dynamic response of a vibrating drill string in a viscous drilling fluid with the energy lost to shear work. It develops the relations for power delivery to the rock as well as the total vibratory power to drive the system. Thus vibratory power losses can be computed by a difference. Part II of this paper applied this theory to a typical effort at developing a rotary-vibratory drilling unit. In the case studied, the power delivery was ineffective and at certain frequencies large losses resulted.

Real-Time Software to Estimate Friction Coefficient and Downhole Weight on Bit During Drilling of Horizontal Wells

2014 ◽  
Author(s):  
Mazeda Tahmeen ◽  
Geir Hareland ◽  
Bernt S. Aadnoy
Keyword(s):  
Friction Coefficient ◽  
Real Time ◽  
Information Transfer ◽  
Horizontal Wells ◽  
Drill String ◽  
Surface Measurement ◽  
Drilling Process ◽  
Drilling Data ◽  
Weight On Bit ◽  
Drag Analysis

The increasing complexity and higher drilling cost of horizontal wells demand extensive research on software development for the analysis of drilling data in real-time. In extended reach drilling, the downhole weight on bit (WOB) differs from the surface seen WOB (obtained from on an off bottom hookload difference reading) due to the friction caused by drill string movement and rotation in the wellbore. The torque and drag analysis module of a user-friendly real-time software, Intelligent Drilling Advisory system (IDAs) can estimate friction coefficient and the effective downhole WOB while drilling. IDAs uses a 3-dimensional wellbore friction model for the analysis. Based on this model the forces applied on a drill string element are buoyed weight, axial tension, friction force and normal force perpendicular to the contact surface of the wellbore. The industry standard protocol, WITSML (Wellsite Information Transfer Standard Markup Language) is used to conduct transfer of drilling data between IDAs and the onsite or remote WITSML drilling data server. IDAs retrieves real-time drilling data such as surface hookload, pump pressure, rotary RPM and surface WOB from the data servers. The survey data measurement for azimuth and inclination versus depth along with the retrieved drilling data, are used to do the analysis in different drilling modes, such as lowering or tripping in and drilling. For extensive analysis the software can investigate the sensitivity of friction coefficient and downhole WOB on user-defined drill string element lengths. The torque and drag analysis module, as well as the real-time software, IDAs has been successfully tested and verified with field data from horizontal wells drilled in Western Canada. In the lowering mode of drilling process, the software estimates the overall friction coefficient when the drill bit is off bottom. The downhole WOB estimated by the software is less than the surface measurement that the drillers used during drilling. The study revealed verification of the software by comparing the estimated downhole WOB with the downhole WOB recorded using a downhole measuring tool.

scholarly journals Improvement of Locally Available Raw Bentonite for Use as Drilling Mud

2017 ◽  
Vol 11 (1) ◽  
pp. 274-284
Author(s):  
Kaffayatullah Khan ◽  
Shaukat Ali Khan ◽  
Muhammad Umair Saleem ◽  
Muhammad Ashraf
Keyword(s):  
Rheological Properties ◽  
Yield Point ◽  
Carboxymethyl Cellulose ◽  
Drilling Fluid ◽  
Gel Strength ◽  
Plastic Viscosity ◽  
Drilling Process ◽  
Drilling Operation ◽  
Bentonite Clays ◽  
Filtrate Loss

Background: Bentonite clays are widely used in a drilling operation and play a vital role as a drilling fluid. Bentonite clay mud performs several functions during the drilling operation and facilitates the drilling process. Objective: In this study, the locally available raw bentonite clays were investigated to evaluate its potential use as a mud for borehole drilling operation after its improvement with the additives. Method: Rheological properties such as plastic viscosity, yield point and gel strength were evaluated by using a viscometer and filtrate loss test was performed by using filter press on both locally available raw bentonite clays and the commercial bentonite named as Mill gel. Results: From the test results obtained for the up gradation of clays with the different beneficiating materials, the drastic increase in the plastic viscosity, yield point and gel strength has been observed. It shows that Xanthum gum produced better results for the improvement of rheological properties of such clays. Carboxymethyl cellulose and starch were used as additives and it has been observed that carboxymethyl cellulose has improved both viscosity and filtrate loss control, whereas starch muds have the best filtration control properties. Conclusion: Improved bentonite clays have rheological and filtration characteristics that have satisfied American Petroleum Institute specification at optimum conditions of clay. It was concluded that improved clays are the suitable material for the drilling operations and suitable to substitute commercial bentonite.

Inline Drilling Fluid Property Measurement, Integration, and Modeling to Enhance Drilling Practice and Support Drilling Automation

2021 ◽  
Author(s):  
Sanjit Roy ◽  
Saiyid Z. Kamal ◽  
Richard Frazier ◽  
Ross Bruns ◽  
Yahia Ait Hamlat
Keyword(s):  
Real Time ◽  
Drilling Fluid ◽  
Measurement Data ◽  
Lessons Learned ◽  
Valuable Insight ◽  
Drilling Process ◽  
Time Data ◽  
Fluid Property ◽  
Real Time Data ◽  
Fluid Properties

Abstract Frequent, reliable, and repeatable measurements are key to the evolution of digitization of drilling information and drilling automation. While advances have been made in automating the drilling process and the use of sophisticated engineering models, machine learning techniques to optimize the process, and lack of real-time data on drilling fluid properties has long been recognized as a limiting factor. Drilling fluids play a significant function in ensuring quality well construction and completion, and in-time measurements of relevant fluid properties are key to automation and enhancing decision making that directly impacts well operations. This paper discusses the development and application of a suite of automated fluid measurement devices that collect key fluid properties used to monitor fluid performance and drive engineering analyses without human involvement. The deployed skid-mounted devices continually and reliably measure properties such as mud weight, apparent viscosity, rheology profiles, temperatures, and emulsion stability to provide valuable insight on the current state of the fluid. Real-time data is shared with relevant rig and office- based personnel to enable process monitoring and trigger operational changes. It feeds into real-time engineering analyses tools and models to monitor performance and provides instantaneous feedback on downhole fluid behavior and impact on drilling performance based on current drilling and drilling fluid property data. Equipment reliability has been documented and demonstrated on over 30 wells and more than 400 thousand ft of lateral sections in unconventional shale drilling in the US. We will share our experience with measurement, data quality and reliability. We will also share aspects of integrating various data components at disparate time intervals into real-time engineering analyses to show how real-time measurements improve the prediction of well and wellbore integrity in ongoing drilling operations. In addition, we will discuss lessons learned from our experience, further enhancements to broaden the scope, and the integration with operators, service companies and other original equipment manufacturer in the domain to support and enhance the digital drilling ecosystem.

Evaluation of Ultrasonic Methods for In-Situ Real-Time Characterization of Drilling Mud

2005 ◽  
Author(s):  
Judith Ann Bamberger ◽  
Margaret S. Greenwood
Keyword(s):  
Physical Properties ◽  
Real Time ◽  
Speed Of Sound ◽  
Direct Contact ◽  
Drilling Fluid ◽  
Drilling Process ◽  
Drilling Mud ◽  
Well Control

A real time multi-functional ultrasonic sensor system is proposed to provide automated drilling fluid monitoring that can improve the capability and development of slimhole and microhole drilling. This type of reliable, accurate, and affordable drilling fluid monitoring will reduce the overall costs in exploration and production. It will also allow more effective drilling process automation while providing rig personnel a safer and more efficient work environment. Accurate and timely measurements of drilling fluid properties such as flow rate, density, viscosity, and solid loading are key components for characterizing rate of drill penetration, providing early warning of lost circulation, and for use in real-time well control. Continuous drilling fluid monitoring enhances drilling economics by reducing the risk of costly drilling downtime, increasing production performance, and improving well control. Investigations conducted to characterize physical properties of drilling mud indicate that ultrasound can be used to provide real-time, in-situ process monitoring and control. Three types of ultrasonic measurements were evaluated which include analysis of in wall, through wall and direct contact signals. In wall measurements provide acoustic impedance (the slurry density and speed of sound product). Through wall and direct contact measurements provide speed of sound and attenuation. This information is combined to determine physical properties such as slurry density, solids concentration and can be used to detect particle size changes and the presence of low levels of gas. The measurements showed that for the frequency range investigated in-wall measurements were obtained over the slurry density range from 1500 to 2200 kg/m3 (10 to 17 pounds solids per gallon of drilling fluid). Other measurements were obtained at densities in the 1500 to 1800 kg/m3 range. These promising measurement results show that ultrasound can be used for real-time in-situ characterization of the drilling process by monitoring drilling mud characteristics.

pH-Sensor Under Consideration for Multi-Sensor-Chip in Downhole Drilling Fluid Monitoring

2017 ◽  
Author(s):  
Jonathan Kühne ◽  
Frederic Güth ◽  
Heike Strauß ◽  
Yvonne Joseph ◽  
Pál Árki
Keyword(s):  
Optical Sensors ◽  
Drilling Fluid ◽  
Drill String ◽  
Glass Electrode ◽  
Drilling Fluids ◽  
Drilling Process ◽  
Ph Sensing ◽  
Drilling Mud ◽  
Ph Sensors ◽  
Drilling Muds

Modern drill strings for the exploration of oil and gas are equipped with a variety of sensor carrying devices such as Measurement While Drilling (MWD), Logging While Drilling (LWD), and Formation Testing While Drilling (FTWD). These devices generate a large amount of downhole data, such as the orientation of the well, drilling parameters e.g. weight on bit and torque, and formation properties. Appropriate telemetry systems are included in the drill string to transfer relevant downhole data in real time to the surface. Other data is stored in memories downhole for subsequent evaluation. However, drilling fluid properties are still monitored at the surface and their behavior under borehole conditions is predicted with hydraulic models. Commercial solutions for a direct downhole measurement of various drilling fluid parameters are rare, though they would increase drilling process safety and the knowledge about the behavior of drilling fluids under real bottomhole conditions. The pH has a significant influence on the properties of water-based muds and plays a role in the chemistry of oil-based muds as the water cut in the emulsion increases. Commercial pH-sensing devices, such as the glass electrode, and optical sensors are not appropriate for the pH measurement under bottomhole conditions. Fragility, the insufficient degree of miniaturization, the low temperature and pressure resistance due to the liquid reference electrolyte, and phenomena such as the alkaline error are certain drawbacks of glass electrodes. Often optical sensors often will not capture the whole pH scale and require the medium to be at least slightly transparent for light. The usage of pH-sensors based on EIS (electrolyte-isolator-semiconductor) structures is a possible application of chemical sensors for drilling fluid monitoring under in situ borehole conditions. This paper presents results from a study on the behavior of an EIS structure as a pH sensitive electrode measured vs. a commercial Ag/AgCl reference electrode in comparison with a commercial glass electrode. EIS structures are capacitive pH sensors where the sensing layer is generally a metal oxide on a semiconductor substrate. Measurements in basic drilling muds were conducted under constant temperature and atmospheric pressure while the drilling mud was steadily stirred. The mud was titrated from alkaline to acidic conditions with hydrochloric acid and the pH was measured after potential equilibration at the electrodes. The results show a general feasibility for the usage of the proposed sensor. There are still certain challenges to be overcome in the development of a robust and reliable pH-sensing device for complex fluids, such as drilling muds under high pressure/high temperature (HP/HT) conditions.

Analysis of Hydraulic Jarring Dynamics and Calculation of Impact Force

2014 ◽  
Vol 577 ◽  
pp. 129-134
Author(s):  
Hu Yin ◽  
Neng Luo ◽  
Qian Li
Keyword(s):  
Impact Force ◽  
Drilling Fluid ◽  
Maximum Velocity ◽  
Drill String ◽  
Acceleration Process ◽  
Drilling Process ◽  
Actual Process ◽  
Conservation Of Energy ◽  
Force Calculation ◽  
The Impact

Drilling jar is widely used to solve the stuck pipe incidents in the drilling process. Impact force which is being made during the jarring operation is acting on stuck point to achieve unfreezing effect. Conventional hydraulic dynamic load calculation method is not considering the impact of friction force on stress wave spreading in drill string. In actual process, friction and viscous resistance caused by the movement of drill string in drilling fluid, making drill string acceleration process exhibiting damped vibration characteristics. Therefore, with the drill string damping vibration theory, analysis of dynamics of acceleration process can be made, and displacement and velocity equation in longitudinal acceleration process can be deduced. Thus the maximum velocity of drill string before collision has been calculated, and impact force acting on the stuck point has been deduced with the law of conservation of energy and momentum. The model of impact force calculation is more satisfied with actual environment in the wellbore during jarring operation.

scholarly journals DESIGN OF SHAFT-BLADE ASSEMBLY FOR EFFECTIVE UTILIZATION OF MUD USED IN OIL AND GAS DRILLING

2013 ◽  
pp. 239-242
Author(s):  
B.SOMI NAIDU ◽  
M.K. NAIDU ◽  
S.SRINIVASA RAO
Keyword(s):  
Oil And Gas ◽  
Drill String ◽  
Drilling Process ◽  
Formation Pressure ◽  
Economic Aspects ◽  
Effective Utilization ◽  
Drilling Operation ◽  
Gas Drilling ◽  
Blade Assembly ◽  
Oil And Gas Drilling

Mud has prominent role in drilling operation, it enhances to protect the drilling well from blowout by obstructing the formation pressure and failure. It gives exact information about presence of formation gasses and fluids at every part of the drilled hole. It‘s very essential to maintain mud with different proportions to have proper and un-interrupted drilling process. Because estimating earth formation is of much difficulty and active mud should readily available at every instant. In order to have proper and un-interrupted drilling process and to maintain mud with different proportions mud activating devices viz., mud-agitator and mud gun are used in existing mud tanks. On observation it is found that nearly 33% of mud in the tank is not influenced with these activating devices. Due to which the flow of mud from the tanks to the drill string is not in exact composition and also there is accumulation of mud chemicals[17] at the bottom of the tank which causes several problems. This paper emphasizes the design of shaft-blade assembly which runs horizontally along the length of the tank in order to activate mud in that tank effectively. The shaft-blade assembly was designed and analyzed in the ANSYS and from the results it was found that the stresses in the shaft-blade materials are well within the limits for the proposed design. Economic aspects of the design are also discussed in this paper at the end.

scholarly journals Real-Time Minimization of Mechanical Specific Energy with Multivariable Extremum Seeking

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1298
Author(s):  
Magnus Nystad ◽  
Bernt Sigve Aadnøy ◽  
Alexey Pavlov
Keyword(s):  
Real Time ◽  
Specific Energy ◽  
Optimization Method ◽  
Initial Guess ◽  
Drill String ◽  
Extremum Seeking ◽  
Drilling Process ◽  
Field Development ◽  
Mechanical Specific Energy ◽  
Time Minimization

Drilling more efficiently and with less non-productive time (NPT) is one of the key enablers to reduce field development costs. In this work, we investigate the application of a data-driven optimization method called extremum seeking (ES) to achieve more efficient and safe drilling through automatic real-time minimization of the mechanical specific energy (MSE). The ES algorithm gathers information about the current downhole conditions by performing small tests with the applied weight on bit (WOB) and drill string rotational rate (RPM) while drilling and automatically implements optimization actions based on the test results. The ES method does not require an a priori model of the drilling process and can thus be applied even in instances when sufficiently accurate drilling models are not available. The proposed algorithm can handle various drilling constraints related to drilling dysfunctions and hardware limitations. The algorithm’s performance is demonstrated by simulations, where the algorithm successfully finds and maintains the optimal WOB and RPM while adhering to drilling constraints in various settings. The simulations show that the ES method is able to track changes in the optimal WOB and RPM corresponding to changes in the drilled formation. As demonstrated in the simulation scenarios, the overall improvements in rate of penetration (ROP) can be up to 20–170%, depending on the initial guess of the optimal WOB and RPM obtained from e.g., a drill-off test or a potentially inaccurate model. The presented algorithm is supplied with specific design choices and tuning considerations that facilitate its simple and efficient use in drilling applications.

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