How to Op)mize Produced Water Recycling on Crosslink Gel Fracs

Transcription

1 How to Op)mize Produced Water Recycling on Crosslink Gel Fracs 1

2 Basic Treatment Requirements What Are Your Goals Cons8tuent Slickwater Guar (Linear) Guar (XL) Hybrids (XL) Chlorides (ppm) 14K (anionic) No Limit (ca)onic) 6K 6K 6K Total Hardness (ppm) 5K 2K 2K 2K Iron (ppm) Oil (ppm) TSS (ppm) Boron (ppm) No Limit Bacteria (cfu/ ml)

3 Basic Treatment Requirements What Are Your Goals Cons8tuent Slickwater Guar (Linear) Guar (XL) Hybrids (XL) Chlorides (ppm) 14K (anionic) No Limit (ca)onic) 6K 6K 6K Total Hardness (ppm) 5K 2K 2K 2K Iron (ppm) Oil (ppm) TSS (ppm) Boron (ppm) No Limit Bacteria (cfu/ ml)

4 Cross-linked gel fluids Gel Compa)bility can be maintained over narrow range. TSS, TDS, Chlorides, Hardness and Boron are all issues. Once Gel recipe is developed water quality must remain in a narrow range to maintain gel compa)bility Control of water quality is paramount 4

5 Problem Statement Recycling Produced Water on Crosslink Gel Fracs How Do I Keep Consistent Water Quality using Produced Water on a Crosslink Gel Frac Op8ons: 1. Don t recycle Use fresh water only 2. Use a very low produced water blend rate 3. Homogenize and Maintain Produced Water Quality 5

6 Recycling for Crosslink Gel Fracs Quality Assurance / Quality Control Program Fresh Water Pit Produced Water Storage QA/QC 6

7 Recycling for Crosslink Gel Fracs Quality Assurance Quality Control Program Mix/Recirculate Produced Water Source QA/QC Pre-Frac Bucket Tes)ng Real Time Monitoring of Water Quality 7

8 Recycling for Crosslink Gel Fracs Quality Assurance Quality Control Program Mix/Recirculate Produced Water Source QA/QC Pre-Frac Bucket Tes)ng Real Time Monitoring of Water Quality 8

9 Temperature Stra8fica8on Even a.1 C (.18 F) or greater temperature difference can inhibit mixing Without mixing thermal stra)fica)on occurs Stra)fica)on results in TDS/Chlorides concentra)ng at lower depths, making quality control much more difficult Water age becomes an issue, newer colder water sinks to bobom, warmer water stays in tank longer Bacterial growth is supported Warmer, lighter water Cold water will not rise into the lighter, warmer water Colder, heavier water 9

10 Produced Water Pit Mixing w/aera8on Con8nuous Temperature Measurement: 3 zones monitored Mixing Start Well-Mixed Point Mixing Stop A - Surface B - Surface C - Surface Water Temperature, F Baseline A - Middle B - Middle C - Middle A - Bobom B - Bobom C - Bobom Ambient Ambient Temperature, F Time 1

11 Produced Water Pit Mixing w/aera8on Improved Water Quality, Reduced Bacteria Levels % Reduc8on ATP, pg/ml Loca)on A Loca)on B Loca)on C Increases from Baseline indicate stra8fica8on Baseline 4 min 38 min Average.35 31% Reduc8on Sulfide, mg/ml Loca)on A Loca)on B Loca)on C Average.5. Baseline 4 min 38 min 11

12 Produced Water Pit Mixing w/aera8on Improved Water Quality, Reduced Bacteria Levels ATP, pg/ml % Reduc8on % 8% ATP, pg/ml % 4% 2% % Reduc8on Day % 12

13 Produced Water Pit Mixing w/aera8on Improved Water Quality, Reducers are decreased Total and Ferrous Iron Reduced Total Iron, mg/l Total Iron, mg/l % Reduc8on % 8% 6% 4% 2% % Reduc8on Day % Ferrous Iron, mg/l Ferrous Iron, mg/l % Reduc8on Day % 8% 6% 4% 2% % % Reduc8on 13

14 Mixing Op8ons Aera)ng Mixers Best Mixing Systems Good Transfer Pumps Acceptable on small pits only Aera8ng Mixer Mixer 14

15 Recycling for Crosslink Gel Fracs Quality Assurance Quality Control Program Mix/Recirculate Produced Water Source QA/QC Pre-Frac Bucket Tes)ng Real Time Monitoring of Water Quality X-FRaC, a patented process for using produced water for crosslinked gel fracs 15

16 Pre-Frac TESTING Frac Prep & Gel Baseline Calibrate Transfer Pumps Bucket Tes)ng Calibrate Pumps- Fresh & Produced Baseline TDS, Chlorides and Boron Tie blend rate and water quality results to RPM seing on pump 16

17 Bucket Tes8ng Chloride, mg/l KCl Equivalent Effluent (Read) Effulent (Calculated) * 3.25% 3.38% 4.65% 4.75% 2.9% 21.7% 3.2% 3.9% Percent of Produced Fluid Boron, mg/l % 7.% 6.% 5.% 4.% 3.% 2.% 1.%.% KCl Equivalent Effulent (Read) Effulent (Calculated) * y = 13.54x R² = % 15% 2% 25% 3% 35% Percent of Produced Fluid 17

18 Bucket Tes8ng Calculated Blend Rates to Meet Different KCl Equivalents Target KCl Equivalent % of Produced Water Boron in Blended Water 3.% 19.2% 19 4.% 25.9% 25 5.% 32.5% 32 6.% 39.2% 39 7.% 45.9% 46 18

19 Pre-Frac TESTING Frac Prep & Gel Baseline Pre-frac Gel Compa8bility Blend water, different blend rates Collect & test samples Engineer chemistry to match the fluid 19

20 Gel Compa8bility Tes8ng Rheology Tes)ng Viscosity Gel Stability Break Time 2

21 Crosslink Gel Compa8bility Slide 1 of 2 Gel Test with Borate Crosslinker No Adjustments made Purely trying to iden8fy compa8bility issues Viscosity ( cp) at 1/sec Viscosity vs. Time Instantaneous Borate Crosslink System 25ppt Guar 6/4 Fresh / Treated Produced Water 6/4 Fresh / Untreated Produced Water 1% Untreated Produced Water Temperature (F) Temperature (F) Time (min) 21

22 Crosslink Gel Compa8bility Slide 2 of 2 Temperature effected stability 7/3 Blend showed significant improvement with temperature No changes in crosslinker concentra8on for 7/3 blend No ph adjustment for 7/3 blend No Buffers Viscosity (cp) at 1sec Viscosity vs. Time Delayed Borate Crosslinked Fluid at 25 o F 9-1 and 9-11 Water Samples 6/4 Untreated Water 6/4 Treated Water 6/4 Treated Water, Lower ph 6/4 Treated Water, Adjusted Caustic Concentration 6/4 Treated Water, Adjusted Crosslinker Concentration 7/3 Treated Water 7/3 Untreated Water Time (Minutes) 22

23 Recycling for Crosslink Gel Fracs Quality Assurance Quality Control Program Mix/Recirculate Produced Water Source QA/QC Pre-Frac Bucket Tes)ng Real Time Monitoring of Water Quality 23

24 Real Time Water Quality Monitoring Chloride / TDS Good Indicator of Quality Monitor Blend Consistency For KCl Equivalency Boron To Iden)fy Inhibitor Dose Rate Bacteria Disinfec)on Monitoring Test Influent/Effluent Test Working Tanks Other Parameters ph / TSS / Hardness etc Pump Control Control Pump RPMs Control Blend Ra8os Adjust Blend on-the-fly 24

25 Real Time Water Quality Monitoring Keep Water Quality Consistent Adjust Blend Rate Stage by Stage 8 7 Fresh Water, bbl Produced Water, bbl % Produced 1% Water volume, bbl % % of Produced 6% 4% 2% Pre* Fresh Water, bbl Produced Water, bbl % Produced 26.8% 25.7% 23.8% 27.% 29.8% 3.2% 28.6% 27.7% 3.8% 3.8% 29.6% 27.1% 26.9% 28.8% 29.3% 26.7% % 25

26 Real Time Water Quality Monitoring Keep Water Quality Consistent Chloride, mg/l Pre Stage Number 12 Boron in Produced Water, mg/l KCl Equivalent Produced Water Treated Water Produced Water Pre* Stage Number Treated Water % 6.% 5.% 4.% 3.% 2.% 1.%.% Boron in Treated Water, mg/l KCl Equivalent of the Treated Water 26

27 Case Study Reeves County 25 Horizontal Wells November 212 October 213 First 6 months, 14 wells, fresh water w/ biocide Last 6 months, 11 wells, recycled water w/ Hydrozonix Crosslinked Gel Fluid Same frac crew, similar frac design 27

28 Case Study - % of Produced Water Well by Well Water volume, bbl Fresh Water, bbl Produced Water, bbl % Produced 1.% 8.% 6.% 4.% 2.% % Produced Well Number.% 28

29 Case Study Boron Level Well by Well 12 Produced Water Boron Produced, mg/l Well # Treated Water Boron Blended, mg/l Well # 29

30 Case Study Chloride Level Well by Well Chloride, mg/l Chloride, mg/l 8, 7, 6, 5, 4, 3, 2, 1, 8, 6, 4, 2, Produced Water Well # Treated Water Well 6 #

31 Gel Concentra8on - Fresh Water vs. Recycled Water Gel Concentra8on, % in mass /18/212 1/6/213 3/27/213 6/15/213 9/3/213 11/22/213 Frac Fluid # of wells Gel Concentra8on, % in mass Gel to Proppant Ra8o Fresh Water w/ Biocide : 1 Recycled Water w/ Hydrozonix Fresh Water w/ Biocide Fracturing Date Recycled Water w/ Hydrozonix : 1 31

32 Breaker Concentra8on - Fresh Water vs. Recycled Water Breaker Concentra8on, % in mass.5 Fresh Water w/ Biocide Recycled Water w/ Hydrozonix /18/212 1/6/213 3/27/213 6/15/213 9/3/213 11/22/213 Fracturing Date Frac Fluid # of wells Breaker Concentra8on, % in mass Breaker to Gel Ra8o Fresh Water w/ Biocide : 1 Recycled Water w/ Hydrozonix : 1 32

33 Daily Well Produc8on- Fresh Water vs. Recycled Water Fresh w/ Biocide Recycled w/ Hydrozonix Gas Dailly Equivalent, bbl Liquid Daily, bbl Produc)on Data was available for 1 of the wells. 4 wells with fresh water, 6 wells with recycled water. There was difference in gas produc)on and liquid produc)on between the two groups of wells. The total produc)on for the two groups of wells were similar. 33

34 Takeaways Produced Water can be effec)vely used and op)mized on crosslink gel fracs Homogeniza)on/Mixing of the Produced Water source is important Pre-frac bucket test is important to set up the use of produced water for crosslinked gel frac Real Time analysis is cri)cal to provide a QA/QC program Confirming the compa)bility of recycled water by evalua)ng the frac chemical use X-FRaC has been used successfully on over 1 fracs 34

35 Ques)ons? 35