Society of Petroleum Engineers

Distinguished Lecturer 2009-10 Lecture Season

How to Strengthen and Stabilize the Wellbore during Drilling Operations  

Fred Growcock

M-I SWACO

Wednesday, February 10, 2010

11:30 AM

Petroleum Club of Midland

$20 per person

Abstract

Loss of drilling fluid to the formation is one of the costliest problems that drillers face during well construction.  Until recently, the primary method used to control losses involved incorporating materials in the fluid or in pills to bridge or plug the loss zone. Current technology enables a comprehensive -- and more effective -- approach that includes this remediative method but gives greater emphasis to preventing lost circulation.  This multi-element approach focuses on (a) best drilling practices, including Managed Pressure Drilling techniques; (b) optimization of hardware configuration; (c) use of drilling fluids which inherently inhibit invasion into permeable or fractured zones; (d) minimization of the fluid’s equivalent circulating density; (e) use of wellbore stability models that model rock and fracture mechanics more accurately; and (f) “strengthening” the wellbore.  Wellbore strengthening encompasses a wide variety of techniques, which may be classified as physical, chemical, thermal and mechanical.  Physical techniques include methods to shield the formation from fluid and pressure through deposition of a barrier that behaves in some ways as casing.  Chemical techniques involve changes in composition of the rock and/or pore fluid, thereby altering the fabric and mechanical properties of the rock.  Thermal techniques involve increasing or decreasing the temperature of the wellbore, e.g. by heating or cooling the drilling fluid at the surface.  Finally, mechanical techniques involve pressure-stressing the wellbore, e.g. hoop stress enhancement (stress caging), to increase the apparent fracture gradient of the rock.  By incorporating these technologies and the lost circulation prevention philosophy in the planning of the well and development of the drilling program, it is now possible and economical to drill wells which previously could not be drilled or which incurred unacceptable levels of Non-Productive Time.

Biography

Dr. Growcock is currently serving as Senior Technical Advisor for M-I SWACO in Houston, Texas, where he provides technical support to the company’s worldwide drilling fluid field operations.  He began his career as a Scientist at Brookhaven and Oak Ridge National Labs in the mid-70’s working on coal liquefaction and gasification and nuclear reactor safety, then moved to Dowell Schlumberger to develop acidizing corrosion inhibitors and foamed fracturing fluids.  Subsequently, he joined Amoco Production Company to carry out drilling fluids R&D and served as an Adjunct Professor of Chemical Engineering at the University of Oklahoma.  Dr. Growcock holds Ph.D. and M.S. degrees in Physical Chemistry from New Mexico State University, and B.A. and B.S. degrees in Chemistry from the University of Texas at Austin.  He has authored more than 100 papers and holds a dozen patents on corrosion inhibitors, drilling fluid systems and completion fluid products.