Improved Oil Recovery Pilot Projects. Todd Hoffman Spring Symposium Montana Tech 21 April 2017

Transcription

1 Improved Oil Recovery Pilot Projects Todd Hoffman Spring Symposium Montana Tech 21 April 2017

2 Outline Slide 2 Previous IOR Pilot Tests What s been done, what s worked, and what we ve learned Future IOR Pilot Tests (engineering/design aspects) What is needed, ideas for improvements, where and when

3 IOR Pilot Tests (field studies) Slide 3 Bakken Niobrara Utica Over a dozen pilots have been performed Locations Bakken Niobrara Eagle Ford Permian Eagle Ford Injected Fluids CO 2 Rich N.G. Lean N.G Fluid Delivery Huff-n-Puff Water Surfactant Continuous

4 IOR Pilot Tests - Bakken Slide 4 Locations Richland Co., MT Mountrail Co., ND 7 pilots in MT/ND Bakken 2 in MT and 5 in ND Performed from SPE Gas 3 Water 3 CO 2 1 Natural Gas

5 CO 2 Huff-n-Puff IOR Slide 5 2 Pilot tests (one in MT and one in ND) Injection rates / pressures ~ psi days inj., days soak, ~ 3 months prod. (Pilot Test #1) (Pilot Test #2) Pilot Test #1 Pilot Test #2 Little to no rate increase observed Small production increase Injection / Soak Time Injection / Soak Time

6 CO 2 Huff-n-Puff IOR Slide 6 2 Pilot tests (one in MT and one in ND) Injection rates / pressures ~ psi days inj., days soak, ~ 3 months prod. No additional oil recovered Injected gas observed at offset wells in days Conformance control is an issue

7 Injection rates Water Huff-n-Puff IOR Slide 7 ~1200 bbl/day for two ~45-day cycles (~14 day shut in) No additional oil recovered Frac-hits complicate interpretations (Pilot Test #3) (Pilot Test #3) Water increase due to offset fracturing Little to no oil rate increase observed Oil increase from offset fracturing Significant water rate increase observed due to huff-n-puff injection Water injection times

8 Aside Frac-hits or Well-bashing Slide 8 Fracturing newly drilled well impact production from older offset wells by fracing into the well (can be positive or negative) Most pilot offset wells were impacted by fracture interference

9 Pilot Test #6 - MT Injection rates ~1700 bbl/day for 3 months, then ~900 bbl/day for 4 months Very fast breakthrough times Continuous Water Injection Offset Producer ~880 feet from injector (Pilot Tests #6) (Pilot Tests #6) 2 mi. Slide 9 Pattern Injection Injection Period Injection Injection Period Increased oil rate

10 Pilot Test #4 - ND Injection rates ~1350 bbl/day for 8 mo., then 6 mo. shut in ~380 bbl/day for 8 mo. Water Inj. vs Prod. Volumes X Continuous Water Injection Offset-West ~2 mi. (Pilot Tests #4/7) (Pilot Tests #4/7) Injection Injection Injection Injection Inj. 1 Inj. 2 Inj. Period Period 2 ~1200 Period 1 Period Inj. 2 2 X ~2300 X X Injector ~900 Offset-East Offset-East ~2300 X Slide 10 Pattern Both offset wells very similar Offset-South

11 Pilot Test #7 - ND Injection rates ~1700 Mscf/day for 2 months Most encouraging of all pilots Slide 11 Continuous Natural Gas Injection All wells have increased oil production (2 wells complicated by frac hits) (Pilot Tests #4/7) (Pilot Tests #4/7) Also looked at offset wells North and South of injection well Offset-North Injection Injection Injection Injection Inj. 1 Inj. 2 Inj. 1 Inj. 2 Period Period 2 Period Period 2 Offset-North Gas Injection Gas Injection

12 Summary Previous Pilots Slide 12 Collectively we have learned from preliminary pilots: Injectivity is not really an issue (gas or water) Recovery is Mixed Eagle Ford looks really good Bakken appears more variable Lots still to be learned Areas to improve

13 What do you want to learn? General Reduce risks (technical and economic)/costs Learn potential problems and correct before full field implementation Specific 1. production rates/volumes 2. injection rates/volumes 3. optimize injection concentrations 4. advance rate of front 5. swept zone residual saturations 6. volumetric sweep efficiencies EOR Pilot Testing - General Design Considerations Slide Location - average reservoir area best area may mask potential problems with process worst area may hide true potential of the method 2. Wells - poor or damaged wells have disastrous effects on pilots 3. Monitoring - what data is needed, how frequently to get note: Watch for oil that escapes outside the pattern 4. Timelines - can be very long

14 EUR Map Pilot Location Slide 14 Criteria for Location Good primary production Easily unitized Data (logs, cores, fluids, etc.) exists Close to source injection fluids

15 South Belridge Diatomite Steamflood (extreme example) Phase 1 1 injection wells ( ) Phase 2 2 injection wells ( ) Phase 3 9 injection patterns ( ) Phase 4 25 injection patterns (c ) aka initial field development EOR Pilot Timelines EOG Unconventional EOR Pilots 2008 Bakken CO Bakken water injection Eagle Ford single well huff-n-puff test 2014-present 3 Eagle Ford multi-well huff-n-puff tests well Eagle Ford huff-n-puff test: aka initial field development Slide 15

16 Be ready when things go wrong No let s try this and see what happens Potentially some problems with the Bakekn pilots Develop a full contingency plan workflow Implement changes in a timely and efficient manner Contingency Plans Ad hoc changes to Bakken projects Pilot Test #4 Injection rates were reduced Pilot Test #6 Injection well frac stages were isolated (attempted) Pilot Test #7 Production wells were shut-in Slide 16

17 In Addition Parallel Studies Slide 17 Measured and Collected Data Cores, logs, fluids, etc Laboratory Experiments Core flooding, new experiments Numerical Reservoir Modeling Testing various ideas

18 Costs When to do new pilots? Slide 18 Pilots are expensive Cost are reduced now Possibly an opportunity to save And prepare for times when prices are higher

19 Conclusions Slide 19 Potential is enormous (100s of billion bbls remain) - But much more research is needed Initial pilot indications are positive - But limited in scope and interpretation Second generation of pilots are needed - Additional engineering/technology *Pilot Testing & Research*

20 Questions Slide 20 Contact information: Todd Hoffman Montana Tech

21 Improved Patterns Slide 21 Current Pilot Patterns Is there something better? Upper Bakken Shale Production Well Middle Bakken Canadian Bakken Injection Project Injection Well Lower Bakken Shale Three Forks-Bench 1 Can vertically stacked Producer / Injector pairs improve sweep efficiency?