Drilling Control System Research Articles

Observer Design for a Wellbore Drilling System With Downhole Measurement Feedback

The increasingly complex oil and gas wellbore condition and the need of drilling in more challenging downhole environments motivate rising research on the drilling control system based on real-time state feedback or measurements from the bottom of the wellbore. However, due to the complex downhole condition and cost-viability, mud pulse telemetry is normally used in this industry to transmit the downhole measurements to the surface, which can cause a large data communication delay as a result of its low bandwidth and slow mud pulse transmission. Since the major drilling control is on the surface, an observer is required to estimate the real-time states of the drilling dynamics as well as the downhole condition, based on the delayed downhole measurement. In this study, we first construct a drilling system dynamics model with coupled axial and torsional dynamics. Then, with the existence of a large output measurement delay, two chain-observer design strategies are introduced for the case of slowly varying control inputs and that of fast-varying control inputs, respectively. The effectiveness of the proposed observer design methods is shown through numerical results.

Kick control reliability analysis of managed pressure drilling operation

Offshore drilling involves complex operations and equipment; thus, faces many operational challenges, including well control. Managed pressure drilling has been proved to resolve most of these challenges; however, this technology, for the most part, is still in its infancy. This paper explores the safety and reliability assessment of a managed pressure drilling operation by investigating the kick control operation of constant bottomhole pressure technique of managed pressure drilling. In addition, this study seeks to understand the components interactions in an MPD system and their modes of failure. Failure scenarios are first built using a Fault Tree model and then analyzed using a Bayesian Network model. The reliability assessments of kick control operation are performed in two ways: a basic-components approach and a system-barrier elements approach. The analysis identifies communication related components, including network device damage as the most safety-critical component due to their high-level of influence while flowline and pump line blockages/rupture are ranked second-most critical but with limited-level of influence. However, the system-barrier element approach ranks the managed pressure drilling control system as the most safety-critical equipment. Further detailed analysis confirms that the monitoring equipment are the most safety-critical components of the managed pressure drilling control system with Coriolis flow meter and Rig pump exhibiting the most critical monitoring equipment. Additionally, the managed pressure drilling system's components show high degree of dependencies on one another and exhibit non-sequential modes of failure during kick control operation.

Design of Semi-physics Simulation Training System for Offshore Drilling Electrical Engineers

As the automatic drilling control system is more widely adopted in the field of offshore oil drilling, the integration of the control system has brought the electrical engineers more challenges to the system troubleshooting. There is an urgent need to propose a low-cost training solution for electrical engineers. Therefore, a semi-physics simulation training system of offshore drilling specifically designed for electrical engineers is addressed in this paper. To maintain high simulation fidelity, driller chairs and PLC controllers are copied and realized from field. Mathematical models are built to simulate both normal and fault state of the drilling control system. Different faults are realized by changing the setting parameters of model or switching between faulty models. Finally, with the help of virtual reality technology, the 3-D environment of drilling operation is realized to improve the vision performance. Moreover, an instructor station subsystem is designed to evaluate trainer’s performance. Through this simulation training system, the electrical engineers can not only master drilling control system, but also improve the troubleshooting skill.

Research on control system of truck-mounted rig for coalbed methane

The coal-bed methane (CBM) as a kind energy is clean and efficient, also it can become a security risk in mining process if it could not get out of the coal seam. In view of the current large-scale exploitation of coal-bed methane resources, the development of drilling rig for CBM drilling is needed. The parameters and structures were introduced in the paper. The rig uses a highly integrated approach that integrates the required functions on the chassis of the vehicle to meet the needs of rapid installation and transportation. Drilling control system uses hydraulic control and electro-hydraulic control dual control mode, can achieve short-range and remote control operations. The control system include security circuits and electric control system. Through the field trial, it is shown that the rig can meet the construction of the majority of coalbed methane drilling in the country and the performance is stable and the operation is simple.

On the mutual relations of drill monitoring variables and the drill control system in tunneling operations

The mutual relation between Measurement While Drilling (MWD) parameters in percussive-rotary drilling is investigated in order to limit the number of MWD variables, and to select the more significant ones, that are required for a sound rock mass characterization. Cross-correlation of the MWD signals is used to determine their relations, the analysis of which brings a thorough understanding of the way that the rig control system governs the different parameters. Data recorded from six drilling machines, working in semi-automatic and manual mode, on three different rock types with different logging interval, have been analyzed. The results point out the feed pressure as the lead parameter that drives the adjustment of the other variables to optimize the drilling, thus being the upfront response to variations in the rock mass. Control parameters that limit this adjustment to minimize disturbances during the operation are also discussed. Finally, the influence of the rock mass condition on the MWD parameters response is studied.

Collaborative Approach to Implementation Helps Realize Benefits of Drilling Automation

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 184695, “Development to Delivery—A Collaborative Approach to Implementing Drilling Automation,” by Riaz Israel, SPE, Julian Farthing, SPE, and Hamish Walker, BP; Rodrigo Gallo Covarrubias and Jason Bryant, Schlumberger; and Christian Vahle, KCA Deutag Drilling, prepared for the 2017 SPE/IADC Drilling Conference and Exhibition, The Hague, 14–16 March. The paper has not been peer reviewed. The application of automated technologies to the process of well construction is emerging as key to improving the overall efficiency of drilling performance. Though not yet mainstream, several recent applications have demonstrated that technology maturity is no longer the limiting factor in accelerating implementation and realizing the benefits of automation. This paper describes a collaborative effort between an operator, a drilling contractor, and a service company to introduce specific aspects of automated technology to a major drilling operation. Project Context and Technology Business Drivers In 2012, the company began developing a giant gas greenfield that required nearly 300 wells to be drilled. Among the many challenges on a project of this magnitude was the need to drive well-construction costs down. An important aspect of well-construction cost is the time spent drilling, which is largely influenced by the slow rate of penetration (ROP) prevalent in the field because of the high rock strength. In order to deliver the performance enhancements required, the company set up an integrated hard-rock drilling team. In addition to the objective of increasing ROP, several other aspects of the technology made it attractive. These include that Automation presents a systematic approach to improve consistency of performance across multiple rigs and wells. Automation can supplement the competency and capacity of drillers. Automation Project Goals In early 2014, the company agreed on a plan to bring this technology to the field in collaboration with the project’s major drilling contractor and drilling service provider (DSP), the supplier of the drilling automation technology. Additionally, because the drilling rig was recognized as a major component of the technology delivery, the company engaged in focused discussions to build alignment with the main drilling contractor to ensure that the right resources were available throughout the project. Finally, the DSP and the drilling contractor implemented a bilateral agreement that covered the scope of work and protected each party’s contribution to the project. With all this in place, the project deliverables were defined as follows: Complete three open-loop field trials of the DSP’s ROP-optimization software, and evaluate the opportunities and areas for improvement. Design, build, and test an interface between the DSP’s automation system and the drilling contractor’s drilling control system. Install the DSP’s drilling automation systems and interface with operator-designated drilling rigs. Complete three closed-loop field trials of the DSP’s drilling automation systems, and evaluate the opportunities and areas for improvement.

Исследование надежности блока отклонения системы управления буровым устройством

Исследование надежности блока отклонения системы управления буровым устройством

Drilling Automation Saves Rig Time and Safeguards Against Human Error

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 177825, “Breakthrough in Drilling Automation Saves Rig Time and Safeguards Against Human Error,” by Egill Abrahamsen, SPE, and Ronny Bergerud, Sekal, and Roald Kluge and Matthew King, Statoil, prepared for the 2015 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, 9–12 November. The paper has not been peer reviewed. This paper shows how automation reduces invisible lost time and allows drillers to focus on other activities while repetitive tasks are controlled by software. An automated drilling-control system using advanced modeling of well conditions in the North Sea helped the rig save up to 10% of rig time per well through safeguarding and optimizing manual operations and automating repetitive activities such as tripping, pipe filling, connections, and pump startup. Introduction To explain why the real-time model-based automated system deployed on the rig was capable of saving up to 10% of rig time, the following factors must be considered: The effect that time and temperature have on drilling-fluid properties and thereby why conventional operations must be kept at a conservative level compared with automated operations tuned to current downhole conditions The reduction of invisible lost time and the realization of faster, smoother drilling operations with fewer unplanned drilling events, obtained through shorter connection times, automated pump startups and shutdowns, automated friction tests, and active (automated) safeguards and safety triggers that assist drillers during manual operations The human factors and team efforts to optimize operations further wherever possible Drilling Fluid Some of the main functions of the drilling fluid are to cool the drill bit; transport drill cuttings out of the wellbore; and maintain downhole pressures to avoid fluid influx or formation collapse, prevent fluid losses, and avoid formation fracturing.

Experience From Hardware-in-the-Loop Testing of Drilling Control Systems

Summary Modern drilling ships and rigs are equipped with advanced computer systems for dynamic positioning, power generation and distribution, and drilling operations. It is well-known that software errors may lead to delays and nonproductive time and may compromise safety. Although the testing and verification regime for structures and machinery systems is well-established, most of the computer systems on today's drilling vessels are put into operation without independent testing and verification. Hardware-in-the-loop (HIL) testing is a test methodology used in several other industries. It facilitates the systematic testing of control-system design philosophy, functionality, performance, and failure-handling capability, in both normal and off-design operating conditions, and is conducted in a virtual test bed in which there is no risk to personnel, vessel, or equipment. Automatic drilling systems that rely on software to function properly often consist of a combination of components delivered by several suppliers. This means that, to maintain safety and to achieve the desired operational performance, control-system software from several suppliers must also run and work together as an integrated system. Marine Cybernetics has finalized the testing of drill-floor control systems for seven rigs, involving nine different vendors. This paper presents experiences from these projects in terms of project execution, test timing, and vendor cooperation and participation. Examples of typical observations are also presented.

An Industrial Robot Based Drilling System for Aircraft Structures

In order to realize automatic flexible drilling with high efficiency and good quality, a drilling system was established, which integrates the technology of laser measurement, off-line programming, computer control and robotics. In this system, the key coordinate frames are established by the laser tracker, the drilling programs are generated by the off-line programming and simulation system, the communication between the automatic drilling control system and the robot control system is based on the socket technique. By running drilling program, the moving platform, robot and the end effector can work automatically and harmoniously. In addition, the deviation compensation methods of hole position and its normal vector are proposed. The experimental results show that the efficiency of drilling can achieve 6 holes per minute, the position accuracy can be effectively controlled within 0.3mm, and the normal accuracy is better than 0.5°.

Design of Telerobotic Drilling Control System with Haptic Feedback

The paper deals with the design of control algorithms for virtual reality based telerobotic system with haptic feedback that allows for the remote control of the vertical drilling operation. The human operator controls the vertical penetration velocity using a haptic device while simultaneously receiving the haptic feedback from the locally implemented virtual environment. The virtual environment is rendered as a virtual spring with stiffness updated based on the estimate of the stiffness of the rock currently being cut. Based on the existing mathematical models of drill string/drive systems and rock cutting/penetration process, a robust servo controller is designed which guarantees the tracking of the reference vertical penetration velocity of the drill bit. A scheme for on-line estimation of the rock intrinsic specific energy is implemented. Simulations of the proposed control and parameter estimation algorithms have been conducted; consequently, the overall telerobotic drilling system with a human operator controlling the process using PHANTOM Omni haptic device is tested experimentally, where the drilling process is simulated in real time in virtual environment.

Collaborative innovation: the decade that radically changed drilling performance

This article sheds light on key factors associated with innovations that are mainly based on experiential learning. The history of a company engaged in the offshore oil and gas industry exemplifies the points: Hitec started out as a small company with limited financial resources, but over a 10-year period, its innovations and improvements radically transformed offshore oil and gas drilling operations. An evolutionary methodological approach is balanced by theoretically informed analysis. A main finding is that customer–supplier interaction was crucial. Hitec's success, crowned by its eventual acquisition by American capital, can be attributed in part to the know-how and technology provided by one of its suppliers and partners during the early phase. However, it has also depended on a series of other factors: a flexible, motivated and creative organisation; targeting of the right know-how; being part of a cluster and thus enjoying easy access to important customers and suppliers as well as easy, informal flow of ideas and information; developers and entrepreneurs prepared to take risks; being in the right place at the right time; a good measure of luck; the underdeveloped state of American drilling control technology; Norwegian oil and gas policies supportive of domestic technological companies; and proximity to research labs which were conducting full-scale tests of drilling operations. An invention made by regional researchers can also be linked to Hitec's innovation of a drilling control system. The relevance of the article is its contribution to a better understanding of the complexity involved in the implementation of major practice-based innovations – a process which includes identifying and creating ideas; finding a market/customer and putting the ideas into practice.

Safe Mud Pump Management while Conditioning Mud: On the Adverse Effects of Complex Heat Transfer and Barite Sag when Establishing Circulation

For complex drilling operations with narrow geo-pressure windows, it is not uncommon to have problems with formation fracturing, due to erroneous mud pump management. To assist the driller in managing the circulation, it is possible to limit both the acceleration of the mud pumps whilst changing the flow-rate as well as the actual flow-rate, to avoid generating downhole pressure above the fracturing pressure gradient of the open hole section. Such mud pump operating limits are dependent on the operational parameters (e.g. drill-string axial and rotational velocities), and the in situ conditions downhole. The in situ conditions evolve with time due to the changes of bit and bottom hole depths as well as the variations in temperature, mud properties and cutting concentrations. When starting to condition mud after a long period of time without circulation, the changes in temperature can be very large. Furthermore, in the eventuality of barite sag, lifting up drilling fluids containing a large concentration of high gravity solid can cause much increase of the downhole pressure. This paper presents a methodology that is used in an automatic drilling control system to account for all those factors in order to have a safe mud pump management including circumstances where mud is being conditioned.

Offshore Field Test of a New System for Model Integrated Closed-Loop Drilling Control

Summary A new system for real-time optimization and automated control of the drilling process has been tested successfully on the Statfjord C platform in the Norwegian sector of the North Sea. The demonstrated system uses continuously calibrated dynamic process models combined with real-time drilling-data input to calculate available parameter windows, and forward-model simulations are applied to provide optimized operational parameter sequences. The calculation results are applied directly in machine control. The system further applies automated testing combined with continuous diagnostics to provide process advisory. In the field test, pipe-movement control automation, pump-rate control automation, and automated wellbore-condition diagnostics were demonstrated, proving fail-safe application of process safeguard enforcement and optimization of operational procedures. Results from active and passive testing indicated that the new methodology has the ability to improve drilling-process reliability, safely increase drilling efficiency, and reduce the risk of human error. The authors provide a thorough description of the preparations and testing and present an evaluation of the test results, with reference to success criteria that were developed in cooperation with the field operator and drilling contractors involved in the test. Implications for the work organization are also discussed, particularly in relation to control of data input, decision making, and responsibility. The demonstrated technology applies direct integration of current know-how and best practices into the drilling-control system, and available real-time information is applied directly in controlling the drilling process.

Technology Focus: Drilling Management (August 2009)

Technology Focus Last April, I had the opportunity to attend the VI Technical Meeting on Well-Engineering Risk Analysis, at Petrobras University, Rio de Janeiro, Brazil, dedicated entirely to risk management in the area of well engineering. That 3-day meeting gave participants an excellent opportunity to exchange experiences, disseminate know-how and current procedures, and discuss problems and critical developments in the area of risk management for drilling and completion operations. I was amazed by the number of diversified works as well as the quality of the presentations, panels, and roundtables. Several topics related to drilling management were presented including risk management for well-control operations, risks involved in the implementation of new technologies, risk analysis for prediction of time and costs in deepwater drilling and completion, the effect of drilling costs on the evaluation of new exploration opportunities, and many others. It is clear to me that drilling management is related closely to risk management. The correct assessment of all risks involved in drilling operations will provide better planning and consequently will improve operational results. Our featured papers bring some examples of better-quality results obtained through superior planning. Project managers, drilling engineers, drilling supervisors, and field engineers will all benefit from careful planning. As most of us should know by now: "If you fail to plan, then you plan to fail" (Saladis and Kerzner 2009). References Saladis, F.P. and Kerzner, H. 2009. Bringing the PMBOK Guide to Life—A companion for the Practicing Project Manager, 49. Hoboken, NJ: John Wiley and Sons. Drilling Management additional reading available at OnePetro: www.onepetro.org SPE 119287 • "Probabilistic Well-Time Estimation Revisited" by A.J. Adams, SPE, Nexen Petroleum, et al. SPE 114797 • "Advanced Drilling Simulation Proves Managed-Pressure Drilling (MPD) Economical in Gasfield Developments in Western Canada" by Geir Hareland, SPE, University of Calgary, et al. SPE 120848 • "Systems Approach and Quantitative Decision Tools for Technology Selection in Environmentally Friendly Drilling" by O.-Y. Yu, SPE, Texas A&M University, et al. IPTC 12707 • "Automatic Calibration of Real-Time Computer Models in Intelligent Drilling-Control Systems—Results From a North Sea Field Trial" by H.P. Lohne, SPE, International Research Institute of Stavanger, et al.