STUCK PIPE PREVENTION UPGRADE II: DIFFERENTIAL STICKING

DIFFERENTIAL STICKING TRAINING MATERIAL UPGRADE RE: STUCK DRILL PIPE PREVENTION COURSE

By Dr Michael Gibson

Wellideas.co.uk are pleased to announce the upgrade of the Differential Sticking Section of their Stuck Pipe Prevention Course which has been held world-wide for 15 years now, which is the only Stuck Pipe Prevention Course which covers both Drilling Engineering and Drilling Operational Aspects. Also, because of covering both the Drilling Engineering and Drilling Operational aspects of Stuck Pipe Prevention, Wellideas.co.uk have advised several Operators and Drilling Contractors on a Drilling Consultancy basis worldwide to prevent Stuck Pipe from occurring on their drilling rigs and platforms – and, just as importantly, how to get free should the Drill String / BHA become stuck in this way.

Today’s high drilling costs necessitate the avoidance of Stuck Drill Pipe. Otherwise, wells can be lost or cost far more than budgeted for. Stuck Pipe Prevention requires both excellent Drilling Engineering, Drilling Consultancy and Drilling Operations – both onshore in the planning phase and offshore in the operational phase.

It is a multi-faceted and complex area, involving Geology, Drilling Planning and Engineering, Directional Drilling Expertise, Drilling Consultancy, Drilling Fluids Composition, Mud Weight and Excellence in terms of personnel on-board the Drilling Rig – both 3rd. Party (e.g., mud loggers, the drilling fluids engineer, the “Company Man” and geologists) and Drilling Contractor personnel. The first schematic shows an overview of Differential Sticking to assist with the understanding of this subject area. It shows thick mud filter-cake causing the drill pipe to become stuck due to: a) the thickness of the filter-cake itself, b) the mud weight being highly overbalanced with respect to the pore pressure itself within the formation (which is highly porous and permeable) and c) non-rotated drill pipe.

The second schematic shows how the high side-wall forces can occur in a directional well, which exacerbates differential sticking risk. The key risks with such wells are a) high side-wall forces due to the well’s design; b) the degree of hydrostatic pressure with respect to pore pressure; c) the thickness of the filter-cake; d) the surface area of the drill-string likely to become stuck; e) whether the drill-string has been rotating prior to becoming differentially stuck, f) the porosity and permeability of the rock formation and e) the composition of drilling fluid used.

Schematic of Differentially Stuck Drill-string across a Permeable Formation which has become Differentially Stuck within Thick Filter Cake
Schematic of Directional Well where high sidewall forces of the Drilling Assembly readily “push” the Drill-string into Wellbore Wall Filter Cakes at high angle) Causing Stuck Drill String

The third schematic, shown below, shows the “pressure mechanism” behind Differential Sticking – showing the importance of the Filter Cake, Rock Porosity & Permeability, and the differences between Hydrostatic & Formation Pressure.

Schematic of a well where high sidewall forces of the Drilling Assembly readily “push” the Drill-string / BHA into the Wellbore Wall Filter Cake

This second section of the updated Wellideas Stuck Pipe Prevention Course – i.e., Differential Sticking, begins by discussing the key reasons as to how and why the drill pipe and the BHA can become stuck “Differentially” when drilling for oil, gas, condensate, or geothermal wells. These areas are 1) Mud Weight Overbalance, 2) Mud Filter Cake, 3) Drill Pipe / BHA Surface Exposure to the “Thick” Mud Filter Cake, 4) Drill String Movement, 5) Mud Properties and 6) Drill-string / BHA movement.

The Differential Sticking Section then goes on to discuss what the Driller’s “First Warning” signs are regarding becoming stuck, which includes what the Mud Loggers, the Rig’s Mud Engineer, the Rig’s Geologist and Computerised Equipment can do to assist in the prevention of Stuck Pipe through this sticking mechanism.

The next section of this course discusses, in detail, what the Driller’s First Actions should be upon coming stuck – which are crucial part of the “fight” to become free – including “Jarring” and “Drill Pipe / BHA” movement – torsionally and longitudinally.

Who is Dr Michael T. Gibson?

Dr Michael T. Gibson has 40 years in the Oilfield, working initially as a Drilling Engineer when he studied Mechanical and Offshore Engineering at Bachelor’s, Diploma and Master’s, Degree Level at Robert Gordon’s in Aberdeen under the expert tutelage of Professor Blythe McNaughton. He then went on to take a PHD over an 8-year period whilst working offshore as a Drilling Supervisor.

He began teaching / lecturing full-time 15 years ago in many parts of the world for Oil Companies, Drilling Contractors and Universities and has written the vast bulk of Wellideas’ material, ranging from Manuals, Pocket Handbooks, PowerPoints and Videos for the Classroom and Zoom Meetings, through to E-Learning Modules for distance learning.

Citations

  • SPE 64114 PA “Differential Sticking Mechanisms and a Simple Wellsite Test for Monitoring & Optimizing Mud Properties” by P.I. Reed
  • “Drilling Fluids Differential Sticking Tendency Determination” Technical Paper by Katarina Simon
  • “Differential Pressure & Mechanical Pipe Sticking” by The International Association of Directional Drilling.