IMoDD: Intelligent Mapping of Downhole Dynamics

2021 ◽  
Author(s):  
Kelly Scott Sims ◽  
John Abhishek Bomidi ◽  
William Anthony Moss ◽  
Thomas Andrew Wilson

Abstract With the ever-increasing pressure to drill wells efficiently at lower costs, the utilization of downhole sensors in the Bottom Hole Assembly (BHA) that reveal true downhole dynamics has become scarce. Surface sensors are notoriously inaccurate in translating readings to an accurate representation of downhole dynamics. The issue of 1 to 1 interpretation of surface to downhole dynamics is prevalent in all sensors and creates a paradigm of inefficient drilling practices and decision making. Intelligent mapping of downhole dynamics (IMoDD) is an analytical suite to address these inefficiencies and maximize the use of surface sensors, thus doing more with less. IMoDD features a new zeroing beyond the traditional workflows of zeroing the surface sensors related to weight and torque at the connection. A new method, Second-order Identifier of Maximum Stand-pipe-pressure: SIMS, is introduced. The method examines changes in stand-pipe pressure and identifies the point before bit-wellbore contact, using a set of conditions. The resulting calculations of weight and torque are verified with measured values of downhole weight and torque, for multiple stands of drilling in vertical, curve-lateral drilling. After the new zero, the deviation of torque-weight correlations is further examined to reveal the downhole weight changes confirmed also by the downhole sensor data. It is demonstrated that an intelligent mapping system that improves downhole characterizations would improve decision making to facilitate smoother energy transfer thus reducing Non-Productive Time (NPT) and increasing BHA life span.

2021 ◽  
pp. 107754632110310
Author(s):  
Vincent Kulke ◽  
Georg-Peter Ostermeyer

Drilling a wellbore can result in several types of vibration that lead to inefficient drilling and premature failure of drill string components. These vibrations are subdivided based on their operating direction into lateral, torsional, and axial vibrations. Especially in hard and dense formations, high-frequency torsional oscillations are found in the bottom-hole assembly (BHA). These critical vibrations are induced by a self-excitation mechanism caused by the bit–rock interaction. Self-excitation mechanisms are regenerative effects, mode coupling, or a velocity-dependent torque characteristic at the drill bit. To increase drilling performance and reduce tool failure due to high-frequency torsional oscillations, the critical vibration amplitudes localized at the bottom-hole assembly need to be minimized. Increasing the damping of self-excited systems to affect the energy output during vibration is a common approach to mitigate self-excited vibrations. In drilling systems, the achievable damping is naturally limited by the small installation space due to the drilled borehole diameter. Therefore, alternative methods to influence vibrations are necessary. Applying parametric excitation in self-excited systems can result in a parametric anti-resonance and therefore in an energy transfer within different modes of the structure. This allows, among other benefits, improved utilization of the structural damping. In this article, the influence of additional stiffness–based parametric excitation on self-excited torsional vibration in downhole drilling systems is investigated. For this purpose, a finite element model of a drill string is reduced using the component mode synthesis and analyzed with the goal to mitigate torsional vibrations. The multiple degree of freedom drill string model is investigated regarding the additional energy transfer due to the parametric excitation. Robustness of various parameters, especially with regard to the positioning within the bottom-hole assembly, is analyzed and discussed. Additionally, the problem of multiple unstable self-excited modes due to the nonlinear velocity-dependent torque characteristic in drilling systems is addressed.


Author(s):  
Y. D. Mulia

For S-15 and S-14 wells at South S Field, drilling of the 12-1/4” hole section became the longest tangent hole section interval of both wells. There were several challenges identified where hole problems can occur. The hole problems often occur in the unconsolidated sand layers and porous limestone formation sections of the hole during tripping in/out operations. Most of the hole problems are closely related to the design of the Bottom Hole Assembly (BHA). In many instances, hole problems resulted in significant additional drilling time. As an effort to resolve this issue, a new BHA setup was then designed to enhance the BHA drilling performance and eventually eliminate hole problems while drilling. The basic idea of the enhanced BHA is to provide more annulus clearance and limber BHA. The purpose is to reduce the Equivalent Circulating Density (ECD,) less contact area with formation, and reduce packoff risk while drilling through an unconsolidated section of the rocks. Engineering simulations were conducted to ensure that the enhanced BHA were able to deliver a good drilling performance. As a results, improved drilling performance can be seen on S-14 well which applied the enhanced BHA design. The enhanced BHA was able to drill the 12-1/4” tangent hole section to total depth (TD) with certain drilling parameter. Hole problems were no longer an issue during tripping out/in operation. This improvement led to significant rig time and cost savings of intermediate hole section drilling compared to S-15 well. The new enhanced BHA design has become one of the company’s benchmarks for drilling directional wells in South S Field.


Author(s):  
Jialin Tian ◽  
Xuehua Hu ◽  
Liming Dai ◽  
Lin Yang ◽  
Yi Yang ◽  
...  

This paper presents a new drilling tool with multidirectional and controllable vibrations for enhancing the drilling rate of penetration and reducing the wellbore friction in complex well structure. Based on the structure design, the working mechanism is analyzed in downhole conditions. Then, combined with the impact theory and the drilling process, the theoretical models including the various impact forces are established. Also, to study the downhole performance, the bottom hole assembly dynamics characteristics in new condition are discussed. Moreover, to study the influence of key parameters on the impact force, the parabolic effect of the tool and the rebound of the drill string were considered, and the kinematics and mechanical properties of the new tool under working conditions were calculated. For the importance of the roller as a vibration generator, the displacement trajectory of the roller under different rotating speed and weight on bit was compared and analyzed. The reliable and accuracy of the theoretical model were verified by comparing the calculation results and experimental test results. The results show that the new design can produce a continuous and stable periodic impact. By adjusting the design parameter matching to the working condition, the bottom hole assembly with the new tool can improve the rate of penetration and reduce the wellbore friction or drilling stick-slip with benign vibration. The analysis model can also be used for a similar method or design just by changing the relative parameters. The research and results can provide references for enhancing drilling efficiency and safe production.


Author(s):  
Ya. M. Kochkodan ◽  
A.I. Vasko

The article presents the main factors affecting the buckling when drilling vertical wells. The authors study analytically the effect of the weight on the bit and the force of the interaction of a drill string with a borehole wall using a uniform-sized arrangement of the bottom-hole assembly and the borehole wall which is located in a deviated wellbore when drilling in isotropic rocks in case the drilling direction coincides with the direction of the force acting on the bit. Differential equations of the elastic axis of the drill string are worked out. The solutions of these equations have given nondimensional dependences between the technological parameters. The authors have obtained the graphical dependences of the distance from the bit to the “drill string - borehole wall” contact point and the normal reaction of the bottom to the bit and the “drill string - borehole wall” clearance. The dependence for identifying the drilling anisotropy index in oblique beds is obtained. An interrelation between the anisotropy drilling index, the zenith angle, the bedding angle, the bottom-hole assembly, the borehole dimensions and the axial weight on the bit has been established. The authors have studied analytically the effect of the weight on the bit and the force of the “drill string - borehole wall” interaction, when installing the centralizer to the bottom-hole assembly. The differential equations of the elastic axis of the drill string with the centralizer in the bottom-hole assembly are obtained. It is established that with the increase in the axial weight on the bit and the “drill collars - borehole wall” clearance, the distance from the bit to the contact point of the borehole wall decreases; whereas with the increase of the deviation angle and the clearance, the pressure force of the column on the walls increases. It has also been established that the anisotropy drilling index reduces the distance from the bit to the point contact both in a slick BHA and in the bottom hole assembly with the centralizer. The presence of a centralizer in the bottom hole assembly increases the distance from the bit to the contact point between the string and the borehole wall, makes it possible to increase the weight on the bit without the risk of increasing a deviation angle.


2012 ◽  
Vol 3 (2) ◽  
Author(s):  
Beth DeJongh ◽  
Robert Haight

Objectives: To create easy to understand, antidepressant medication decision making aids and describe the process used to develop the aids for patients diagnosed with depression. Methods: In collaboration with the Institute for Clinical Systems Improvement (ICSI), antidepressant medication decision making aids were developed to enhance patient and physician communication about medication selection. The final versions of the aids were based on design methods created by Dr. Victor M. Montori (Mayo Clinic) and discussions with patients and providers. Five physicians used prototype aids in their outpatient clinics to assess their usefulness. Results: Six prototype antidepressant medication decision making aids were created to review potential side-effects of antidepressant medications. The side effects included were those patients feel are most bothersome or may contribute to premature discontinuation of antidepressant treatment, including: weight changes, sexual dysfunction, sedation, and other unique side effects. The decision aids underwent several revisions before they were distributed to physicians. Physicians reported patients enjoyed using the decision aids and found them useful. The sexual dysfunction card was considered the most useful while the daily administration schedule card was felt to be the least useful. Conclusions: Physicians found the antidepressant decision making aids helpful and felt they improved their usual interactions with patients. The aids may lead to more patient-centered treatment choices and empower patients to become more directly involved in their treatment. Whether the aids improve patient's medication adherence needs to be addressed in future studies.   Type: Student Project


2020 ◽  
Vol 4 (3) ◽  
pp. 179-190
Author(s):  
Budi Setiadi

ABSTRAKSalah satu faktor yang mempengaruhi daya keluaran listrik dari panel surya adalah posisi dan tingkat penyerapan sinar UV (Ultraviolet) dari matahari. Penggunaan aktuator motor servo untuk solar tracker membebani listrik yang dihasilkan dari pembangkit internal panel surya. Pada penelitian ini dirancang solar tracker menggunakan silinder pneumatik sebagai pengganti aktuator motor servo. Sedangkan, sensor UV digunakan untuk memantau sudut pergerakan matahari. Nilai error dan Δerror dari hasil pengolahan data sensor UV menjadi masukan bagi sistem pengambilan keputusan berbasis kendali fuzzy. Keluaran sistem pengambilan keputusan ini mengatur pergerakan posisi silinder pneumatik naik, turun, atau stop. Pengujian perangkat bekerja dengan baik, menghasilkan respon dinamik overshoot 5,3 % dan error steady state 1,6 %.Kata kunci: ultraviolet, pneumatik, fuzzy, overshoot, errorABSTRACTOne of the factors that affect the electrical output power of solar panels is the position and the absorption level of UV (Ultraviolet) rays from the sun. The use of a servo motor actuator for solar trackers burdens the generated electricity from the solar panels internal generator. In this study, a solar tracker was designed using a pneumatic cylinder as a replacement for the servo motor actuator. While a UV sensor was used to monitor the angle of the sun’s movement. The error and Δerror values from UV sensor data processing results become an input for decision-making systems based on fuzzy control. The output of this decision-making system regulates the movement of the position of the pneumatic cylinder up, down, or stopping. The test device worked properly, resulting in a dynamic response overshoot of 5.3% and a steady-state error of 1.6%.Keywords: ultraviolet, pneumatic, fuzzy, overshoot, error


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