Horizontal Drilling Pilot In a Shallow Heavy Oil Reservoir in Northwestern Romania Authors: John Lavelle, Amin Yaghoobi
About Suplac Oil Field Discovered 1958 Oil Density 960 kg/m3 (16 API) Viscosity 2300 cp Area 1700 hectares 70 sections Cold production 1960 (0.5t/well/day) Fireflood started 1964 Oil to date 20 million tonnes Current rate ~1000 t/d from 750 wells 2 Horizontal Drilling Pilot Suplac 2010
About Suplac Reservoir Unconsolidated sand Depth 80 to 200mTVD, dipping to north Thickness 10 to 25 metres Fireflood line-drive and cyclic steam Schist basement below the sand Southern boundary is a fault Northern Boundary is the Oil-Water contact 3 Horizontal Drilling Pilot Suplac 2010
Challenges Using a vertical mast rig, can we turn to horizontal in 200mTVD or less? Will the unconsolidated sand be stable when drilling 300m drains? Will wellbores maintain integrity under steam injection and oil extraction? Will equipment work liner, slots, pumps? Will the project be economic? 5 Horizontal Drilling Pilot Suplac 2010
Execution Timeline Reservoir proposal 2008 Pilot go-ahead Q2 2009 Well concept Q3 2009 Slotted liner testing Q1 2010 Peer reviews, tendering, ordering Q2 2010 Location construction Q3 2010 Spud August 22, 2010 6 Horizontal Drilling Pilot Suplac 2010
Location Selection Undeveloped area of reservoir Sufficient TVD Available utilities close to existing electricity, steam and oil lines Chosen site: Directional offsets to 60 degrees and 12/30m DLS Low risk of shallow losses 7 Horizontal Drilling Pilot Suplac 2010
Map 8 Horizontal Drilling Pilot Suplac 2010
Map 9 Horizontal Drilling Pilot Suplac 2010
Well Construction BOP Waiver 20 at 5m 12 ¼ hole 9 5/8 TB casing 9 5/8 N80 Tenaris Blue casing Thermal cement to surface Liner hanger 9 5/8 close to base reservoir until an inclination of 93+ (parallel to basement) Horizontal slotted liner is placed in open hole through the zone Steam injection through a 3 1/2 tubing, thermal expansion joint and thermal packer Production through conventional rod pump / linear rod pumping unit 8 1/2 open hole, 7 slotted liner Pannonian 300 meter 11 Horizontal Drilling Pilot Suplac 2010
Equipment Rig Top drive 75 tonne stroking mast design Small footprint typically under 1000 m2 (1800 here) Conventional DD tools PDM, MWD, GR Logs DP conveyed memory tools Liner flush joint, fine slots, hydraulic rotating running tool, reamer shoe 12 Horizontal Drilling Pilot Suplac 2010
Rig 13 Horizontal Drilling Pilot Suplac 2010
Operations Drilled centre well in 26 days with two plugbacks total losses at limestone top Drilled the West well in 12 days with one plugback (trajectory) horizontal at 197.55mTVD Drilled the East well in 20 days with two plugbacks (trajectory, losses) and an open hole sidetrack at 201mTVD in 8 ½ hole 14 Horizontal Drilling Pilot Suplac 2010
Trajectories Section View -20 80 180 280 380 480 580 150 160 170 180 190 H1C Plan H2E Plan H3W Plan H1C H3W H2E Basement Limestone 200 210 15 Horizontal Drilling Pilot Suplac 2010
Trajectories Plan View 643300.00 643200.00 643100.00 643000.00 H3W H1C H2E H1C Plan H2E Plan H3W Plan 642900.00 642800.00 642700.00 316400.00 316450.00 316500.00 316550.00 316600.00 316650.00 316700.00 16 Horizontal Drilling Pilot Suplac 2010
How did we do? Successful shallow KOP of 10m KB Successful shallow landing horizontal at 200mTVD or less in all wells Successful 300m drains in each Successful open hole sidetrack Demonstrated that: The time plan of ~ 10 days is achievable The budget is achievable Production rates of 50 t/day are realistic Slotted liner gives acceptable sand control 17 Horizontal Drilling Pilot Suplac 2010
Trajectory Hole Cleaning RISK LEARNING Immediate KickOff Up to 14/30m DLS At-bit inclination Low flow rates Sidetrack earlier rather than later Cement and open-hole S/T proven Hydraulics models incorrect low flow rates cleaned well High viscosity and weighted sweeps were ineffective Pumping out packoffs occurred Casing to bottom Hole Stability, Differential Sticking No issues Liner running Liner setting Geology No issues rotation, reamer not rqd Prototype tool success Unexpected uncertainty losses in limestone 19
Thank You! john.lavelle@petrom.com Paper Title: Horizontal Drilling Pilot in a Shallow Heavy Oil Field in NorthWestern Romania Authors: John Lavelle and Amin Yaghoobi, OMV Petrom S.A., Romania