# Risks to Drinking Water from Oil and Gas Wellbore Construction and

Integrity Case Studies and Lessons Learned

Briana Mordick 

# Oil & Gas Science Fellow Natural Resources Defense Council 1

# BAINBRIDGE TOWNSHIP, OHIO Case Study 1

2

# Incident Summary

• December 15, 2007: Explosion at a home in Bainbridge Township, Geauga County, OH 

# • Investigators determine natural gas is entering homes via water wells 

# • Ohio Department of Natural Resources, Division of Mineral Resources Management (DMRM) evaluates local oil and gas wells to 

# determine source of natural gas • Ohio Valley Energy Systems Corp (OVESC) identifies problems with their English No. 1 well, assumes responsibility for incident, and 

# initiates corrective action • DMRM initiates monitoring program, measures response of water 

# wells to corrective action at the English No. 1, performs remedial water well work, provides methane monitoring equipment to 49 

# homes, and provides replacement drinking water to 48 homes.
3

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell 

# Simplified Stratigraphy at English No. 1

3600 - 3900’ TARGET FORMATION 4

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing

5

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing Surface Casing Fully Cemented

6

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing Surface Casing Fully Cemented



## TD = 3926’ 7

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing Surface Casing Fully Cemented Production Casing



## TD = 3926’ 8

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing Surface Casing Fully Cemented Production Casing



## TD = 3926’ 9

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing Surface Casing Fully Cemented Production Casing Open Annulus



## TOC = 3640’ TD = 3926’ 10

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing Surface Casing Fully Cemented Production Casing Open Annulus



## TOC = 3640’ TD = 3926’ 

# Perfs = 3720 - 3740’ 11

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing Surface Casing Fully Cemented Production Casing Open Annulus



## TD = 3926’ 12

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing Surface Casing Fully Cemented Production Casing Open Annulus



## TD = 3926’ 13

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing Surface Casing Fully Cemented Production Casing Open Annulus



## TD = 3926’ 14

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing Surface Casing Fully Cemented Production Casing Open Annulus



## TD = 3926’ 15

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing Surface Casing Production Casing Fully Cemented Open Annulus



## TD = 3926’ 16

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing Surface Casing Production Casing Fully Cemented Open Annulus



## TD = 3926’ 17

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing Surface Casing Production Casing Fully Cemented Open Annulus



## TD = 3926’ 18

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing Surface Casing Production Casing Fully Cemented Open Annulus



## TD = 3926’ 19

## Glacial Till

Aquifers Ohio Shale “Big Lime” Oriskany

Newburg 

## Clinton Packer Shell Conductor Casing Surface Casing Production Casing Fully Cemented Open Annulus

“Out-of- zone” hydraulic fracture growth allows gas to migrate from the Clinton formation into the open annulus behind the production casing. During primary cement job, large volume of cement goes into the highly porous Packer Shell “thief zone” , resulting in poor primary cement job. As a result of the poor cement job, the shallow Ohio and Newburg gas - bearing zones are left open behind casing and the gas migrates into the annulus. 

### 1 

### 2
3



## TD = 3926’ Surface- production casing annulus is shut in for 31 days and becomes overpressured, allowing gas to migrate horizontally and vertically into drinking water aquifers. 

### 4

20

# Areas of Dispute
• Was the over- pressurization of the annulus 

# sufficient to fracture the geologic units exposed in the wellbore? 

# • If so, could these fractures create a permanent migration path for gas to reach groundwater? 

# • Can methane gas concentrations in domestic water wells be used to delineate such fracture networks? 

# • What is the nature and origin of the presence of black particulate matter in some domestic water 

# wells? 21

# MAMM CREEK FIELD, GARFIELD COUNTY, COLORADO Case Study 2

22

# Study Area

Source: USGS 2011 USGS, 2011

23

# Study Area

Source: USGS 2011 URS, 2006 Papadopulos, 2008 Thyne, 2008

24

# Incident Summary
• West Divide Creep Seep: COGCC detects BTEX compounds, methane, and heavy 

# hydrocarbons (C2 - C6) in West Divide Creek resulting from a poor cement job in a nearby gas well 

# • Due to water contamination incidents and increased gas drilling, Garfield County, CO commissions a series of studies to assess the risks to surface and groundwater from gas well development and human activities • The United States Geological Survey (USGS), in cooperation with the Colorado 

# Department of Public Health, also undertakes a study to determine the sources and sinks of nitrate and methane in Garfield County domestic water wells 

# • Sampling of domestic water wells shows elevated concentrations of methane; groundwater quality health standards are exceeded for fluoride, selenium, nitrate, and arsenic; aesthetic standards are exceeded for chloride, iron, manganese, and 

# total dissolved solids (TDS).

– Fluoride and selenium do not appear to be related to oil and gas activity

– Nitrate concentrations most likely related to agricultural activity, septic system effluent, and 

## animal waste

– Domestic water well hydrogeochemistry shows evidence of mixing between shallow groundwater and deep formation water in some wells 25

# Areas of Dispute
• Temporal correlation of methane and chloride 

# contamination and natural gas activity • Nature and origin of methane in water wells

– Thermogenic vs. Biogenic

– Related to natural gas extraction? 

# • Primary mechanism for deep Wasatch and/or Mesaverde formation water to mix with 

# groundwater
26

# Nature and Origin of Methane in Groundwater STUDY METHANE TYPE ORIGIN TRANSPORT URS, 2006 Biogenic Biogenic origin Not discussed URS, 2006 Thermogenic Thermogenic origin • Natural fractures • Gas drilling and production activities/ improperly abandoned wells URS, 2006 Mixed/Unknown Uncertain origin Possible mixed sources Papadopulos, 2008 Biogenic Biogenic origin Indeterminate Papadopulos, 2008 Thermogenic Conventional thermogenic, coalbed thermogenic, oxidized biogenic, or mixing Indeterminate Thyne, 2008 Thermogenic Conventional thermogenic or Microbial reduction of thermogenic Mesaverde CO 2 to CH 4 Ga s drilling and production activities USGS, 2011 Biogenic Deep Wasatch • Natural fractures • Uncemented gas well annuli USGS, 2011 Thermogenic Mesaverde thermogenic and oxidized biogenic • Natural fractures • Uncemented gas well annuli 27

# Nature and Origin of Water Types

STUDY WATER TYPE ORIGIN TRANSPORT URS, 2006 Na/Ca/Mg- HCO 3 Shallow groundwater Precipitation/recharge URS, 2006 Na -SO 4; Na -SO 4- HCO 3 Unknown Unknown URS, 2006 Na - Cl Deep groundwater • Fracture zones/structural features • Gas wells Papadopulos, 2008 Mixed cation - bicarbonate anion,

low TDS Shallow groundwater Precipitation/recharge, flow along shallow pathways Papadopulos, 2008 Na - HCO 3; Na -SO 4 (high TDS) Shallow or deep groundwater • Precipitation/recharge, flow along shallow pathways • Vertical upward flow along natural fractures, wellbores, or hydraulic fractures Papadopulos, 2008 Na - Cl Deep groundwater/brine • Natural deeper flow processes Thyne, 2008 Low TDS, Ca - Na - Mg- HCO3 Streams and water wells near surface streams Precipitation/recharge Thyne, 2008 Higher TDS, Na - Ca - HCO3 -SO4 Water wells, deeper/not near streams Precipitation/recharge Thyne, 2008 Higher TDS, Na - Cl Williams Fork Formation ( Mesaverde ) produced water Gas drilling and production activities USGS, 2011 High - oxygen, high - nitrate, lowmethane; mixed cation -SO4- HCO3, mixed cation - HCO3 -SO4; young or mixed age Shallow groundwater (Evidence in some wells of septic system effluent, animal waste, fertilizer) Precipitation/recharge USGS, 2011 High - oxygen, high - nitrate, lowmethane; mixed cation -SO4- HCO3, mixed cation - HCO3 -SO4; old Deeper groundwater (not Mesaverde ) Precipitation/recharge USGS, 2011 Low- oxygen, low- nitrate, high methane; Na - HCO3 to Na - Cl ; mixed age or old Primarily Mesaverde formation water mixed w/some shallow groundwater • Natural fractures • Uncemented gas well annuli 28

# Key Observations
• The study area is naturally faulted and fractured. Fault and fracture density 

# increases near structural features, such as the Divide Creek Anticline • For new wells:

– Surface casing must be set below the lowest USDW and cemented to surface

– Production casing must be cemented to 500’ above the top of gas in the Mesaverde (Williams Fork)



## – The deep Wasatch may be left open to the annulus

– Older wells may have been constructed using different standards 

# • Gas production wells with persistent or recurring elevated bradenhead pressures have been identified near structural features • Domestic water wells with elevated methane and chloride concentrations are often coincident with structural features • Natural fractures and faults may

– Provide natural migration pathways for gas and fluids, both to groundwater and to the 

## uncemented annular space of wellbores

– Cause complications in well drilling, construction, and completion 29

# Challenges

• “Most water supplies within the Bainbridge investigation area do not have water analyses predating 

## local oil and gas activities.” (DMRM, 2008) • “Due to the absence of historic water quality data prior to drilling of gas wells to serve as a baseline 

## in the area, the water quality issues observed in the study area could predate gas well drilling activities. We cannot make a definitive statement other than the water quality issues could be caused by natural conditions and/or potentially the presence of gas wells in the area.” (URS 2006) 

## • “Domestic wells (are) not placed to determine sources of contamination in groundwater. They are not evenly spaced around gas wells or within close enough proximity to determine the presence of chemicals associated with methane that degrade rapidly.” (Thyne, 2008) • Construction and abandonment practices for older wells may pose a higher risk for migration of methane to groundwater. ( Papadopulos, 2008) • “The cementing problems encountered at the Schwartz 2 - 15B gas well are evidence that the presence of fractured intervals in this area may also affect cement integrity in gas well 

## completions” (URS, 2006) • “The effect on groundwater due to the introduction of drilling or well completion/ hydrofracturing fluids into the shallow aquifer was not investigated for this study. A study evaluating possible local effects of drilling or hydrofracturing fluids on domestic groundwater should be considered.” (Papadopulos, 2008) 30

# Solutions & Lessons Learned • Detailed site characterization and planning

– Geologic and hydrologic



# – Baseline water chemistry

– Gas sampling and composition (vertical and aerial)



# – Temporal and aerial updates 

# • Wellbore construction and maintenance

– Hydrocarbon and brine bearing zones must be isolated



# – Wellbore integrity and workovers 

# • Water quality monitoring plan and dedicated 

# monitoring wells • Hydraulic fracture modeling and measurement • Must consider cumulative impacts
31

# References
• Bair, E.S., Freeman, D.C., and Senko, J.M., 2010, Expert Panel Technical Report, Subsurface Gas Invasion Bainbridge Township, Geauga County, Ohio: Prepared for the Ohio Department of Natural Resources Division of Mineral Resources Management • Donato, S.A., Sterrett, R.J., and Hanna, B., 2009, Review of the Thyne Report’s Analysis and Conclusions of Mamm Creek Phase II Hydrogeologic Study: PowerPoint presentation prepared for the Colorado Oil & Gas Conservation Commission, 10 p., http://cogcc.state.co.us/Library/Presentations/Glenwood_Spgs_HearingJuly_2009/(1_F)_ReviewOfTheThyneReport'sAnalysi s_Conclusionof%20MammCreekPh2.pdf • Eckstein, Y., 2009. Wellhead LEL records in Bainbridge residential water wells, PowerPoint presentation to Bainbridge Gas Invasion Expert Panel, 43 p., www.ohiodnr.com/mineral • Gorody

, Anthony, 2009, Summary Comments on the Report by Dr. G. Thyne : PowerPoint presentation prepared for the Colorado Oil & Gas Conservation Commission, 26 p., http://cogcc.state.co.us/Library/Presentations/Glenwood_Spgs_HearingJuly_2009/(1_G)_Summary_Comments_Report.ppt • McMahon, P.B., Thomas, J.C., and Hunt, A.G., 2011, Use of diverse geochemical data sets to determine sources and sinks of nitrate and methane in groundwater, Garfield County, Colorado, 2009: U.S. Geological Survey Scientific Investigations Report 2010–5215, 40 p. • Ohio Department of Natural Resources, Division of Mineral Resources Management, “Report on the Investigation of the Natural Gas Invasion of Aquifers in Bainbridge Township of Geauga County, Ohio” September 1, 2008 • Papadopulos & Associates, Inc., 2008, Phase II hydrogeologic characterization of the Mamm Creek Field area, Garfield County, Colorado: Prepared for the Board of County Commissioners, Garfield County, Colorado, 41 p. • Papadopulous & Associates, Inc., 2009, Evaluation of Thyne, 2008 “Review of Phase II Hydrogeologic Study” Mamm Creek Field Area, Garfield County, Colorado: PowerPoint presentation prepared for the Colorado Oil & Gas Conservation Commission, 29 p., http://cogcc.state.co.us/Library/Presentations/Glenwood_Spgs_HearingJuly_2009/(1_D)_Evaluation_of_Thyne_Report_vers 2%20(dv).pdf • Thyne, Geoffrey, 2008, Review of Phase II Hydrogeologic Study prepared for Garfield County: Prepared for Garfield County, 26 p., http://cogcc.state.co.us/Library/Presentations/Glenwood_Spgs_HearingJuly_2009/(1_A)_ReviewofPhase - II HydrogeologicStudy.pdf • URS Corporation, 2006, Phase I hydrogeologic characterization of the Mamm Creek Field area in Garfield County: Prepared for the Board of County Commissioners, Garfield County, Colorado, 86 p. 32