About this Virtual Instructor Led Training (VILT)
The drill string is the simplest piece of equipment in use on a drilling rig and at the same time, the most critical piece. We use the qualifier ‘basic’ because although 99% of the drill string comprises plain tubes that are just screwed together, the lowest section, just above the bit, can go to extreme loading and is fitted with highly sophisticated electronics packages providing both positional and lithological data as well as a steering system to drive and orient the bit.
The principle tasks of the drill string are also deceptively simple. These are to:
- Convey each drill bit to the bottom of the hole and then to retrieve it when worn,
- Act as a conduit to convey drilling fluid at high pressure down to the bit and
- Transmit torque from surface to bit, occasionally in concert with a hydraulic motor to drive this bit.
This 4 half-day Virtual Instructor Led Training (VILT) course will cover in detail what it takes to decide on minimum drill string specifications, which are able to support the loads to which it will be subjected. In addition to the need to use a drill string with minimum strength requirements, we also need to ensure that we can prevent drill string failure. If the failure consists of a small split or leak of any kind, then the time involved may be little more than that required for a roundtrip to change the bit. If the string parts, then the recovery is likely to take a considerable amount of time. In a worst case scenario, the fish in the hole may prove impossible to retrieve, requiring a sidetrack.
A less than optimal design of the string will reduce the efficiency of the operation and almost always leads to premature bit wear. This is particularly true when we are unable to measure and control the dynamics of the drill string as a whole and the bottomhole assembly in particular. Axial vibrations, torsional vibrations and lateral vibrations may take place in various degrees of severity. The behaviour of the drill string while operating under torsional vibrations is thought to be of great importance and may result in torsional buckling.
This VILT course will also cover the drilling optimization limiters, how to identify them and how to remove them. This is done by understanding the drill string dynamics – by operating under the most favourable conditions and by measuring the dynamics in the vicinity of the bit (or at the bit) in order to make timely adjustments.
The VILT course homes in what office staff needs to know and plan for and what field staff needs to know and implement. By the end of this VILT course, participants will be familiar with:
- Critical dimensions of common drill pipe and weld-on tool joints and its relation to yield for calculation of tensile, torsional and burst resistance.
- Make-up torque of connections that relate to the tool joint dimensions and the torsional strength of that connection.
- Use of design factors and safety factors on tensile and torsional strength in relation to new and worn state. Conditions which could lead to drill pipe collapse.
- Situations where limitations on sinusoidal (snake) and helical buckling will apply and the influence of radial clearance and deviation.
- Failure of drill pipe (fatigue) and the circumstances under which these would occur (rotation across doglegs, pipe in compression etc).
- Mechanism under which hardbanding would induce casing wear and the methods applied to measure and prevent any significant wear.
- Drill pipe inspection methods we apply to identify early flaws/cracks/corrosion, to measure dimensions, to inspect tool joints etc.
- Common BHA components, including heavy wall drill pipe, their external/internal dimensions, connections (API, proprietary) and appearance (such as spiral).
- Significance of thread compounds to ensure the correct make-up torque is applied.
- Significance of drill string/BHA ‘neutral point’ in the context of drill string component failure.
- Basic design principles for a BHA make-up in a vertical, low/medium deviated and highly deviated well in terms of weight transfer and drag/torque.
- Stabilization principles for a pendulum (vertical), a stabilized (vertical or tangent), a build and a drop-off assembly.
- BHA design and stabilization in relation to mitigation/elimination of vibration and to the elimination of tension, torsion or fatigue failure.
- Matching bit aggressiveness, gauge length, BHA stabilization, steerability and Mechanical Specific Energy (MSE) to mitigate the severity of any vibration.
- Bit efficiency and reduction of wear by understanding mechanical and hydraulic limiters. How to perform a passive or active drill-off test.
- Importance of being conversant with API 7G RP and/or equivalent data books, to look up/check the recommended tensile/torque and other parameters for the drill string in use.
The VILT course is intended for staff directly or indirectly involved in the delivery of challenging wells such as junior to senior well engineers, both in office-based planning and operations and field-based operator/contractor supervisory staff such as company men and toolpushers.
The VILT course will be delivered online in 4 half-days consisting 4 hours per day, with 2 breaks of 10 minutes per day.
Course Duration: 4 half-day sessions, 4 hours per session (16 hours in total).
To further optimise your learning experience from our courses, we also offer individualized “One to One” coaching support for 2 hours post training. We can help improve your competence in your chosen area of interest, based on your learning needs and available hours. This is a great opportunity to improve your capability and confidence in a particular area of expertise. It will be delivered over a secure video conference call by one of our senior trainers. They will work with you to create a tailor-made coaching program that will help you achieve your goals faster.
Request for further information about post training coaching support and fees applicable for this.