REAL-TIME TESTING OF ROCK CUTTINGS DURING DRILLING Presented by: Irene Ronoh 2018 G2G INNOVATION SEMINAR, PRIDE INN SPA & RESORT 18TH JUNE - 22ND JUNE 2018

IRENE RONOH Geologist – Olkaria JOH-KGN001-20071212-JvW-X1 IRENE RONOH Geologist – Olkaria Currently enrolled at Reykjavik University for MSc in SUSTAINABLE ENERGY PGCert. Geothermal Technology (UoA-New Zealand) PGDip. Borehole Geology (UNU-GTP-Iceland) BSc in Geology (UoN)

Presentation Outline 1 2 3 4 5 Introduction: Conceptual Idea Challenges/Case studies 2 Opportunities/Proposed Solution 3 Cost Benefit Analysis 4 Recommended Next Steps 5

CONCEPTUAL IDEA

Introduction: Drilling a well Collect rock cuttings after every 2m of drilling INTRODUCTION Depth of 3000-3500m 50-60 days-Time taken to drill a well Cost between USD 3-5 million Cost include drilling services, material and equipment, supervision, infrastructure

cont’ Drilling fluid-Aerated mud, Water, stiff foam, air Rock cuttings carried to the surface by drilling fluid Smectite clays can present in the cuttings Expansive structure- swell when too much water is absorbed

Case Studies Smectite abundance in the well Entrapment of the drill string OW-724V, OW-906, OW-905B and OW-922 Downtime cost per day USD 27,000

CHALLENGES OW-724V (2013/2017) 729m-29 days High smectite at 700 m JOH-KGN001-20071212-JvW-X1 CHALLENGES Six plug jobs to stabilize formation OW-724V (2013/2017) 729m-29 days High smectite at 700 m Stuck at 793 m. Free the string-150 days Cased and abandoned Drilling resumed in 2017- 226 days USD 11,541,414

OW-906 (2012) TD 2200m-187 days 300 m-Swelling of clays Downtime-due to reaming, plug job/wait on cement, freeing drill string Cost of drilling well about USD 7,546,166

OW-905B (2013) OW-905B 829 m-135 days 400-700 m- smectite clays Freeing stuck drill pipes -40 days Later, plug and abandoned Cost of well to 829 m about USD 5,058,521

OW-922 (2014) 3000 m-89 days Abundant smectite clays 400-600 m JOH-KGN001-20071212-JvW-X1 Use of a dispersant (Calgon) but corroded the drill pipes-Better to anticipate and thus change drilling fluid to stiff foam/ aerated OW-922 (2014) 3000 m-89 days Abundant smectite clays 400-600 m 1100-1300 m Major swelling of clays at 1260 m Extra 67 days-major downtime Total cost amounts to about USD 10,939,600

Current situation X-Ray Diffractometer (XRD) analysis After well completion 150 carefully selected samples for clay analysis Analysis takes 2 months (slow, expensive) To fast track, outsource the services/ buy and extra machine-more expensive Process currently affected by slow procurement procedures (Safety badges)

PROPOSED SOLUTION Geologist Drilling crew

Proposed analytical method Methylene Blue (MeB) Kit Onsite chemical analyses done by a rig geologist Cheaper and quicker Decisions are made when drilling is ongoing

How it works Using about 1g of acidified sample Methylene Blue dye test (MeB Test) Using about 1g of acidified sample Add MeB dye progressively until all absorbed Blue halo indicate saturated smectite

COST BENEFIT ANALYSIS Equipment, Materials, Software, Reagents JOH-KGN001-20071212-JvW-X1 COST BENEFIT ANALYSIS Equipment, Materials, Software, Reagents O&M costs

Training, Safety badges JOH-KGN001-20071212-JvW-X1 Personnel cost Training, Safety badges

DISCUSSION One XRD machine present in the laboratory JOH-KGN001-20071212-JvW-X1 Radiation Protection Board-direct-restricted tendering DISCUSSION One XRD machine present in the laboratory Slow procurement processes during acquisition of X-ray machine parts after breakdown and renewal of X-ray safety badges (Current situation) Sample preparation and analysis is sluggish hence affecting decision making while drilling There’s need to detect swelling clays thus advise on appropriate drilling fluid

Recommendations Methylene Blue Dye test to supplement the clay XRD analysis Decisions on the behavior of the well will be made onsite (while drilling) hence minimize hazards The cost of Methylene Blue kit is estimates at (Ksh 181,185.94) Train the geologists and technicians to use MeB Dye

JOH-KGN001-20071212-JvW-X1 Thank You