SWD Remedia+on and Damage Removal in Oil and Gas Wells with Chlorine Dioxide October 2018 Buenos Aires Brent E. Smith

Transcription

1 SWD Remedia+on and Damage Removal in Oil and Gas Wells with Chlorine Dioxide October 2018 Buenos Aires Brent E. Smith

2 Source of Informa+on The informa;on in this presenta;on was originally published at: Texas Tech - SWPSC in May 2017, Texas U.S.A. The paper is also available from Sabre s exhibi8on booth in the exhibi8on area The paper can be purchased online at: hnps://swpshortcourse.org/ 2

3 Have you ever wondered WHY your SWD refuses to respond to HCL acid? Photo courtesy of Rich SWD in Woods County, Oklahoma And yet, you keep acidizing every month hoping that something different will happen? Sabre Energy Services, LLC 3

4 Have you ever wondered WHY your rod pump well lost all of its produc+on? Just ayer you dumped 1,000 gallons of 15% HCL down the tubing/ casing annulus? Photo courtesy of GE Oil and Gas Sabre Energy Services, LLC 4

5 Agenda Introduc;on What is Chlorine Dioxide (ClO2)? Chlorine Dioxide Genera;on Using Three Pre-Cursors Oilfield Applica;ons of ClO2 Surface and Subsurface Forma;on of Sour Systems Iron Sulfide Contamina;on Biomass / Bacteria / Slime Treatment of Sour Wells with Chlorine Dioxide Lessons Learned from Field Applica;ons Ques;ons Sabre Energy Services, LLC 5

6 What is Chlorine Dioxide? Chlorine Dioxide is a pure gas ClO 2 is generated on loca;on ClO 2 a strong Oxidizer & Biocide ClO 2 is a small, penetra;ng molecule Photo courtesy of ClorDiSys For oilfield applica;ons, we dissolve the pure gas into a liquid (water or hydrocarbon) immediately at the gas genera;on site. Sabre Energy Services, LLC 6

7 Photo courtesy of FOX Venturi generators Sabre Energy Services, LLC 7

8 + 99.5% Sabre Energy Services, LLC 8

9 Sabre Energy Services, LLC 9

10 Damage Removal with Chlorine Dioxide More Damage Removal than S;mula;on fluid Porosity and Permeability ClO 2 does not really increase these; ClO 2 converts solid oxidizable species, or par;culates to water soluble species to re-open porosity and restore permeability. We=ability ClO 2 Treatment leaves the forma;on water wet, thus improving rela;ve permeability. Sabre Energy Services, LLC 10

11 Damage Removal with Chlorine Dioxide Claims to s;mula;on come from the wise use of HCL acid as spear-heads for the ClO 2 and great results (at removing biomass and damage) Looks like s;mula;on ClO 2 and HCL acid are a formidable team Between the aggressive ac;on of these two fluids, almost all damage can be removed from most wellbores (NOT barium and stron;um sulfate) Sabre Energy Services, LLC 11

12 Bug BoNles SRB APB GEN Sabre Energy Services, LLC 12

13 Surface Applica+ons of Chlorine Dioxide 1. Biocide - Prepare ALL Frac waters 2. Recycling Produced water for fracturing 3. Cleaning fluids pre-swd; pre-floods 4. Tank and Pipeline Cleanouts Removes Biofouling and FeS deposits 5. Pits cleaning, biocide treatment; pit closures Note: Surface Biocide applica8ons: Normally < 30 ppm Well S8mula8on / Damage Removal is at 3,000 ppm Sabre Energy Services, LLC 13

14 What Does 3,000 ppm ClO2 Look Like? Sabre Energy Services, LLC 14

15 Sulfate-Reducing Bacterium Photo courtesy of American Society for Microbiology Sabre Energy Services, LLC 15

16 Forma+on of Sour Systems Bacterial Contamina8on of Oilfield systems with Sulfate Reducing Bacteria (SRB s) and other bacteria results in a Sour System SRB s metabolize sulfate and reduce it to sulfide which can exist as H 2 S gas, HS -, S 2- depending on ph (ph 6 = 90% as H 2 S) Sulfide ion can also react with iron in the system to form a solid FeS sludge Sabre Energy Services, LLC 16

17 Damage Removal with Chlorine Dioxide There are two main applica;ons of ClO 2 in damage removal / s;mula;on treatments 1. Bio-remedia8on of producers knock down the H 2 S and SRB s, clean up FeS, (more preven;on). 2. Tradi8onal s;mula;on type treatments where acid and ClO 2 are used in mul;-staged diversion treatments, for damage removal, and restoring the well to what you used to expect. (SPE papers SPE PA and SPE MS) Sabre Energy Services, LLC 17

18 Typical Damage Removal Treatment (>5 stages) Sabre Energy Services, LLC 18

19 The Biggest Source of Iron is the Pipe Itself! Corrosion and Bacteria Photo courtesy of ReStream Solu;ons Sabre Energy Services, LLC 19

20 What Reservoir Damage? Iron sulfide (FeS) (from H 2 S and SRB s) Iron Carbonate (linked oyen to FeS) Calcium Carbonate Polyacrylamide Polymer Gel Filter Cake Biomass! Photo courtesy of mnn mother nature network Blobfish and ugliest animal in 2013 Sabre Energy Services, LLC 20

21 Biomass Synonyms for the Oilfield Biomass Bacterial growth Slime Biofilm Bacterial colonies SRB s Photo courtesy of Steve Spangler Science Sabre Energy Services, LLC 21

22 Biomass Photo courtesy of Environmental Molecular Sciences Laboratory 2014 Founda;on David Suzuki Sabre Energy Services, LLC 22

23 Biomass Photo courtesy of Penny Arcade Sabre Energy Services, LLC 23

24 Biofilm Photo courtesy of Coastal Review Online Biofilms of the sulfate-reducing, anaerobic bacteria Sabre Energy Services, LLC 24

25 Biofilm Photo courtesy of POPULAR SCIENCE Sabre Energy Services, LLC 25

26 Bacterial Biofilms Photo courtesy of Organic Soil Technology Sabre Energy Services, LLC 26

27 Biofilm biofilms of sulfate reducing bacteria (SRB s) Photo courtesy of Clinton Sabre Energy Services, LLC 27

28 Hagfish Biological Slime Photo courtesy of MIMS Sabre Energy Services, LLC 28

29 Hagfish Biological Slime Photo courtesy of DISCOVERY Sabre Energy Services, LLC 29

30 Industrial Slime on a Heat Exchanger Photo courtesy of researchgate.net. Sabre Energy Services, LLC 30

31 Where does the damage come from? The by-products and con;nued growth of bacteria and bacteria colonies (Biomass and slime), in a favorable environment. Sabre Energy Services, LLC 31

32 Bacterial Biofilms From MicrobeWiki Sabre Energy Services, LLC 32

33 Where does the damage come from? 1. The by-products and con;nued growth of bacteria and bacteria colonies (Biomass and slime); in a favorable environment. 2. Scaling tendencies of the fluids in the well and reservoir typically manifests itself in and near the wellbore (Chemistry). When you add the two, you have a real mess Sabre Energy Services, LLC 33

34 Where does the damage come from? Biofouling in dead ends of a pipe Photo courtesy of MERUS Sabre Energy Services, LLC 34

35 Hydrogen Sulfide (H2S) Corrosion Photo courtesy of ReStream Solu;ons Sabre Energy Services, LLC 35

36 Pipe Corrosion a\er Clean-Up Photo courtesy of ReStream Solu;ons Sabre Energy Services, LLC 36

37 Biomass And the best way to iden;fy wells that have Biomass is: Injectors and SWD s stop responding to HCL! Producers proof of Biomass is harder to pin down, but if there are SRB s, FeS, H 2 S, and lots of pump failures, you have all the ingredients for Biomass. Sabre Energy Services, LLC 37

38 Damage Removal with HCL & ClO 2 HCL removes 1. Iron Carbonate 2. Calcium Carbonate, Limestone, Dolomite 3. Iron sulfide (FeS) and iron oxide Chlorine Dioxide removes 1. Biomass and Bacteria (APB and SRB) 2. H 2 S 3. Polymers and polyacrylamides 4. Iron sulfide (FeS) and iron oxide Sabre Energy Services, LLC 38

39 Conven+onal Acidizing Cycle FeS Reprecipitates FeS HCl Acidiza;on Fe 2+ + S 2- H 2 S + Fe Cl - ph Rises Above 1.9 H 2 S is Ionized Conven8onal Acidizing does not remove the biomass or kill bacteria and will redeposit FeS once the ph rises above 2 Sabre Energy Services, LLC 39

40 Enhanced Acid S+mula+on with Chlorine Dioxide ClO 2 Breaks Cycle FeS Acid Stage Fe 3+ FeO(OH) H 2 S + Fe Cl - ph > 4 Iron Hydrolysis Fe 3+ + SO 4 2- Water Soluble H 2 S + FeS Oxidized ClO 2 Stage Sabre Energy Services, LLC 40

41 Key Design Features DIVERSION, DIVERSION, DIVERSION! No Cookie Cu=ers! THINK and Right-SIZE! Pump Rate - both HCL and ClO 2 have rates of reac;on that are quick; get 6-9 BPM HCL acid you must have it (CaCO3, FeCO3) Ahead of and behind the ClO 2 Increasing stage sizes as job progresses Over-Flush the ClO 2 Helps with spent HCL precipitates Clean wellbore Sabre Energy Services, LLC 41

42 Final Notes The generators are made of un-lined mild steel, and last 9 10 years b/n re-builds. High Quality ClO 2 is NOT corrosive Genera8on Method Cri8cal to Safety ClO 2 is safe to use and handle, when people are properly trained and obey simple rules. No Chemical Transfers in the field Inhala8on is main concern with ClO 2 Sabre Energy Services, LLC 42

43 Sabre Energy Services, LLC 43

44 Lessons Learned Every well is different; the biggest mistake an operator with hundreds of wells makes, is to start cookie-cuzng and generalizing Adjust the job design to the well condi8ons Be driven by Results and HSE Make sure you get Diversion! CRITICAL If you want proof of Biomass, do a flow-back Like bo=oms-up plus 50 Bbls Test For H 2 S, all forms of bacteria, ORP, ATP Sabre Energy Services, LLC 44

45 Thank You Brent E. Smith 45