System and method for controlling a drilling path based on drift estimates

A method includes receiving toolface information corresponding to a location of the bottom hole assembly (BHA) with respect to a target drilling path and drift information. The surface steerable system calculates a first toolface vector from a first location of the BHA to the target drilling path to create a convergence path to the target drilling path and calculates an adjustment of the first toolface vector to a second toolface vector to account for system drift defined by the drift information such that the BHA will converge with the target drilling path by drilling in accordance with the second toolface vector. The surface steerable system modifies at least one drilling parameter to alter a drilling direction of the BHA based on the calculated second toolface vector and transmits the at least one drilling parameter to the drilling rig to target the BHA in accordance with the second toolface vector.Board of Regents, University of Texas Syste

Friction reduction optimization for extended reach and horizontal wells

With conventional oil and gas reservoirs declining, energy companies are constructing more complex wells to economically produce natural resources that were not accessible previously. Extended reach Offshore wells and horizontal unconventional land wells are just two examples of technologies developed to unlock challenging reserves. However, torque and drag in extended reach and horizontal wells with departures of ten thousand feet or more still constitute one of the main challenges and technical limitations for drilling. Offshore wells can experience high friction even with the use of rotary steerable systems. Additionally, directional land wells drilled with downhole steerable motor experience high friction because only the bit rotates while the rest of the string slides against the wellbore wall. This friction can produce complications such as low sliding and rotating rates of penetration, high tortuosity, poor hole cleaning, vibrations, premature downhole tools failure or bit damaging and connection back-offs. Additionally, it can stop the string from moving backwards or forwards and rotating, potentially ending up with an irreversibly stuck drillstring and a shorter-than-planned well. In this work, we try to understand the influence of different agents on friction behavior and mitigation in deviated and horizontal wells, and how these agents can be used most effectively while drilling to improve drilling performance and wellbore qualityPetroleum and Geosystems Engineerin

A Sliding Mode Control Based Stabilization Method for Directional Rotary Steering Tool-Face

When the directional rotary steering system works in the state of maintaining the tool face angle, the use of PID control mode will lead to a large swing angle of the tool face angle of the directional rotary steering system. In order to reduce the swing amplitude of the tool face angle, based on the PID position control and the angle position error sliding mode control strategy, the exponential synovial control function is established. The simulation results show that the fast and accurate tool face angle tracking is achieved through the closed-loop control of the angle position. The paper provides an implementation method for the research of directional rotary steering system

Data-Driven Numerical Simulation and Optimization Using Machine Learning, and Artificial Neural Networks Methods for Drilling Dysfunction Identification and Automation

Providing the necessary energy supply to a growing world and market is essential to support human social development in an environmentally friendly. The energy industry is undergoing a digital transformation and rapidly adopting advanced technologies to improve safety and productivity and reduce carbon emissions. Energy companies are convinced that applying data-driven and physics-based technologies is the economical way forward. In drilling engineering, automating components of the drilling process has seen remarkable milestones with considerable efficiency gains. However, more elegant solutions are needed to plan, simulate, and optimize the drilling process for traditional and renewable energy generation. This work contributes to such efforts, specifically in autonomous drilling optimization, real-time drilling simulation, and data-driven methods by developing: 1) a physics-based and data-driven drilling optimization and control methodologies to aid drilling operators in performing more effective decisions and optimizing the Rate of Penetration (ROP) while reducing drilling dysfunctions. 2) developing an integrated real-time drilling simulator, 3) using data-driven methodologies to identify drilling inefficiencies and improve performance. Initially, a novel drilling control systems algorithm using machine learning methods to maximize the performance of manually controlled drilling while advising was investigated. This study employs feasible non-linear control theory and data analysis to assist in data pre-analysis and evaluation. Further emphasis was spent on developing algorithms based on formation identification and Mechanical Specific Energy (MSE), simulation, and validation. Initial drilling tests were performed in a lab-scale drilling rig with improved ROP and dysfunction identification algorithms to validate the simulated performance. Ultimately, the miniaturized drilling machine was fully automated and improved with several systems to improve performance and study the dynamic behavior while drilling by designing and implementing new control algorithms to mitigate dysfunctions and optimize the rate of penetration (ROP). Secondly, to overcome some of the current limitations faced by the industry and the need for the integration of drilling simulation models and software, in which cross-domain physics are uni-fied within a single tool through the proposition and publication of an initial common open-source framework for drilling simulation and modeling. An open-source framework and platform that spans across technical drilling disciplines surpass what any single academic or commercial orga-nization can achieve. Subsequently, a complementary filter for downhole orientation estimation was investigated and developed using numerical modeling simulation methods. In addition, the prospective drilling simulator components previously discussed were used to validate, visualize, and benchmark the performance of the dynamic models using prerecorded high-frequency down-hole data from horizontal wells. Lastly, machine-learning techniques were analyzed using open, and proprietary recorded well logs to identify, derive, and train supervised learning algorithms to quickly identify ongoing or incipient vibration and loading patterns that can damage drill bits and slow the drilling process. Followed by the analysis and implementation feasibility of using these trained models into a con-tained downhole tool for both geothermal and oil drilling operations was analyzed. As such, the primary objectives of this interdisciplinary work build from the milestones mentioned above; in-corporating data-driven, probabilistic, and numerical simulation methods for improved drilling dysfunction identification, automation, and optimization

Design and analysis of robust controllers for directional drilling tools

Directional drilling is a very important tool for the development of oil and gas deposits. Attitude control which enables directional drilling for the efficient placement of the directional drilling tools in petroleum producing zones is reviewed along with the various engineering requirements or constraints. This thesis explores a multivariable attitude governing plant model as formulated in Panchal et al. (2010) which is used for developing robust control techniques. An inherent input and measurement delay which accounts for the plant's dead-time is included in the design of the controllers. A Smith Predictor controller is developed for reducing the effect of this dead-time. The developed controllers are compared for performance and robustness using structured singular value analysis and also for their performance indicated by the transient response of the closed loop models. Results for the transient non-linear simulation of the proposed controllers are also presented. The results obtained indicate that the objectives are satisfactorily achieved

Reducing Produced Water Disposal Via Effective Treatments Methods And Re-Use: Proposed Sustainable Application For Bakken, North Dakota

It is true that the advancements in both the hydraulic frack and directional drilling technologies led to less time and a bit easier ways to develop unconventional oil and gas assets worldwide. In the Bakken North Dakota, the result of these breakthroughs and advancements in technologies are that they drastically reduce the time it takes to drill and complete a well leading to more wells (347 in 2004 to 16,300 in 2020). In 2019, the United States became the largest global crude oil producer, and the unconventional Bakken Play in North Dakota is one of the major contributors to this feat. As more wells are being drilled, more waste water are being produced. Analysis also showed early increases in water cuts even in younger (less than 3 years) wells drilled around McKenzie and Williams Counties. The concern here is that the wastewater produced by these increased oilfield activities is highly saline (~170,000 to 350,000 ppm TDS), and the most commonly used water disposal method in the Bakken Formation is deep injection into disposal wells. Notwithstanding, there are growing environmental and operational concerns about the sustainability and impacts of this approach. However, if the wastewater is efficiently treated, it could be reused in hydraulic fracturing operations or to support coal mining and irrigation activities. This research uses various method to investigate the root cause of the high volume of wastewater production in the Bakken, North Dakota and how these flow back and produced water could be treated using various novel technologies like, the advanced and improved desalination, advanced electro-oxidation and dilution methods. Lastly, the research was able to provide robust and detailed results on how the Bakken treated produced water could be transformed to good use especially as base fluids for hydraulic frack fluid formulation

The effect of well path, tortuosity and drillstring design on the transmission of axial and torsional vibrations from the bit and mitigation control strategies

As well designs become increasingly complicated, a complete understanding of drillstring vibrations is key to maximize drilling efficiency, to reduce drillstring dysfunction and to minimize drillstring, tool, and borehole damage. Torque and drag models exist that seek to quantify the effects of borehole inclination and tortuosity on static friction along the drillstring; however, the effects on dynamic friction remains poorly understood. This dissertation begins with a review of the past fifty years of work on drillstring dynamics models, an overview of the proposed control strategies and a summary deployed vibration mitigation applications within the drilling industry. Derivations from first principles of a series of computationally efficient axial and torsional drillstring models in both the frequency and time domains are then presented and verified with field data. The transfer matrix approach is used to predict the severity of axial vibrations along the drillstring and is verified using a series of case studies using field data. Harmonic axial vibrations within drillstrings are either induced intentionally, in the case of axial oscillation tools midway along the drillstring, or unintentional, in the case of bit bounce. Two case studies of bit bounce are first evaluated to ensure model validity for a harmonic excitation at a the bit and the model is found to accurately predict bit bounce based on surface rotation rates. Induced axial oscillations, generated by axial oscillation tools, are then investigated to quantify friction reduction and drilling efficiency improvements. Optimal placement is found to depend on wellbore geometry, but is usually restricted to periodic regions of the drillstring. These optimizations are then verified using field trials and suggest that improved placement can result in 20% or more reduction in friction along the drillstring. Two applications of torsional drillstring vibrations are then investigated -- stick slip mitigation and drillstring imaging. The time domain form of the torsional drillstring model is used first to evaluate the effectiveness of three types of top drive controllers -- stiff controllers, tuned PI controllers and impedance matching controllers -- in mitigating stick slip oscillations. Then, the transfer matrix method is applied to evaluate the effect of wellbore geometry on drillstring mobility to conclude that higher order modes of stick slip may become dominant in non-vertical wellbores. The feasibility of drillstring imaging using torsional signals from surface is then investigated to identify inputs and methods that show promise in three setups of varying complexity -- a hanging beam, a laboratory drillstring model and a drilling rig. Two techniques show promise -- white noise injection and model fitting of a step response -- in identifying larger features, including drillstring length and BHA location. However, low sampling frequencies and low bandwidth inputs reduce the ability to image small features such as friction points along the wellpath.Petroleum and Geosystems Engineerin

A first-principles directional drilling simulator for control design

A directional drilling simulator was constructed using a re-formulation of first-principles classical mechanics in order to serve as a platform for advanced control design. Dedicated focus was placed on building a modular solution that would interface with an existing Supervisory Control And Data Acquisition (SCADA) architecture. Model complexity was restricted to include only the features required to make an immediate step change in tool face control performance through more accurate determination of torsional dead time and time constant values. Development of this simulator advanced the art of drilling automation by building a foundation upon which developers may design novel control schemes using big data gathered in the modern oilfield. This first-principles model is supported by theoretical formulation of equations of motion that capture fundamental behavior of the drill string during both rotary and slide drilling operations. Wellbore trajectory was interpolated between survey points using the Minimum Curvature Method, and a semi-soft-string drill string model was assumed. Equations of motion were derived using energy methods captured in both Hamiltonian and Lagrangian mechanics and solved using the finite-element method. Transient dynamic solutions were obtained using Newmark integration methods. A sensitivity analysis was conducted to determine which parameters played the most influential roles in dynamic drill string behavior for various operational scenarios and to what extent those parameters influenced torsional dead time and time constant calculations. The torsional time constant was chosen as a measure of correlation between case studies, due to the significant role this value plays in state-of-the-art tool face control algorithms. Simulation results were validated using field data collected from rigs using a SCADA system to operate in various shale plays in North America. Results from field tests were used to compare torsional time constant values calculated using manually-determined, simulation-based, and analytical methods and investigate directional drilling performance over a range of operational scenarios. Simulation-based time constant calculation results were consistently more accurate than analytically-determined values when compared to manually-tuned values. The first-principles directional drilling simulator developed for this study will be adopted by the existing SCADA system in order to standardize and improve slide drilling performance.Mechanical Engineerin

Investigation on dynamics of drillstring systems from random viewpoint

Drillstrings are one of the critical components used for exploring and exploiting oil and gas reservoirs in the petroleum industry. As being very long and slender, the drillstring experiences various vibrations during the drilling operation, and these vibrations are random in essence. The first part of the thesis focuses on stochastic stick-slip dynamics of the drill bit by a finite element model and a single degree of freedom drillstring model in Chapters 3 and 4, respectively. In the single degree of freedom model, the path integration (PI) method is firstly used to obtain the probability density evolution of the dynamic response. Then Monte Carlo (MC) simulation is used for validating PI results and conducting the parametric study. The second step of my research is to study the stochastic dynamics of a vertical, multiple degrees of freedom drillstring system. The work of this part is presented in Chapter 5. The novelty of this work relies on the fact that it is the first time that the statistic linearization method is applied to a drillstring system in the bit-rock interaction to find an equivalent linear dynamic system which is then solved with the stochastic Newmark algorithm. After that, the stick-slip and bit-bounce phenomena are analyzed from random viewpoint. The third step of my research move on to directional drilling. A static study of directional drillstring from random viewpoint is presented in Chapter 6. The finite element method (FEM) based on the soft string model is employed and built. Then two strategies are taken to model the random component for hoisting drag calculation. The purpose of this work is to analyze the effects of the random component on hoisting drag calculation by the MC simulation method