Shell Day Unconventional Gas Footprint Reduction Challenge
UNCONVENTIONAL GAS-FOOTPRINT REDUCTION CHALLENGE Team Members: Akhil Prabhakar Swapnil Pal Dheeraj Agrawal Shishir Arya IIT ROORKEE
Presentation Flow • Prototype Small Footprint Drilling Rig • NOx Air Emissions Studies • Development of Ultra-deep Drilling Simulator (prototype) EFD’s • Innovative Water Management Technology to Reduce Environmental Impacts of Produced Water • FeaturesEco-Centre Waste Management Facility • Pursuing Efficiencies in well drilling and completion • Pursuing Efficiencies in Production Operations Efficiencies of • Pursuing Efficiencies in Water Treatment and Disposal CONCLUSIONSTraditional Wells • Pursuing Efficiencies in finding and Development Costs
Environment Friendly Drillings (EFD’s)• Prototype Small Footprint Drilling Rig• NOx Air Emissions Studies• Development of Ultra-deep Drilling Simulator (prototype)• Innovative Water Management Technology to Reduce Environmental Impacts of Produced Water
Prototype Rigs Green Completion Multi well Pad Drilling Small Better & Coiled TubingLow Impact Rigs Prototype Innovative Drilling Drilling Drilling Rig Centralized Fracturing Micro hole VSP Imaging
Multi well Pad DrillingMultiwell pad drilling minimizes theenvironmental footprint of drillingoperations while improvingefficiency, enabling simultaneous drillingand completion operations and reducing thenumber of well sites, vehicle traffic and landsurface disturbances.Trinidad Drilling has 29 rigs operating inthe Haynesville Shale, drilling as many aseight horizontal wells from a single pad.
Features:• Ground level assembly without crane.• Raise the mast and drill floor in one single shot.• Raising system is built in to the substructure.• Integrated mast sections and drill floor with drilling equipment.• Mast stem sections are compact in size.• Traveling block will be strung up to the crown block during rig move.• Mast will include built-in guide rail.• B.O.P. Handler & Transporter will keep the B.O.P. assembled during rig move. Source: Veristic Manufacturing
Positives Constraints drives efficiency gains Is not efficient for shallow depth drilling drilling, fracturing Requires monitoring at each stage and producing all at the same time reduces land disturbances for access roads, vehicle traffic and trenching for gathering lines and production infrastructure. Opportunity 1. Constraints can be blown up by combining various techniques.
• One may think that this method has become a bit obsolete with the development of techniques like Coiled Tube Drilling.• With countries like India almost finished with shale gas policy formulations, these techniques must be given importance.
Central FracturingWilliams Production RMT Company isusing centralized pads to hydraulicallyfracture multiple tight gas sands wellson 10-acre spacing from a single centralpad location in the Piceance Basin inColorado. Working on as many as 22wells simultaneously, the company hasfractured as many as 140 wells from acentralized location, some as far asthree miles away.
Positives Constraints Gets the gas to market quicker Proper pipeline infrastructure required reduces surface disturbance by using existing pads for frac equipment supports reusing produced Opportunity water to pump hydraulic fracturing treatments 1. Proper choice of technique on the basis of ecosystem. For a single pad, it reduces water truck trips by at least 30%
Positives Constraints Limited Availability of “fit for purpose” Faster Mobilization and demobilization Units Faster Trip times Maintaining DOT weight Restrictions while sustaining mobilization benefits Limited number of BHA’s Capable of Smaller Footprint two phase drilling Continuous circulation during Tripping Opportunity: Less site preparation and Remediation 1. Increased BHA availability 2. BHA cost reduction 3. Additional “fit for purpose” CTD equipments.
Micro Hole VSP Imaging• The opportunity microhole drilling offers for these deep unconventional-reservoir development projects lie in its potential for improved target imaging via low-cost seismic monitoring holes by use of new technologies and methodologies applied to vertical seismic profiling (VSP)• Given better imaging of reservoir “sweet spots,” the industry will not have to drill conventional vertical holes from many closely spaced drilling locations to minimize exploration risk. Micro hole Imaging• Relatively high geologic risk Much lower engineering development risk• It should be used to shrink the smallest conventional hole size of 8.75 in. diameter to at least 3.5 in.
LOW IMPACT RIGS• These rigs adapt to the environment with minimal disturbance.• They are smaller, making them easier to move• They can be more green on combination with pad drilling, they must have skid packages, which minimize surface disturbance and reduce overall well costs.• They have rounded bottom tanks, having side valves that vacuum trucks can access to suck the fluid out more efficiently, reducing chances of spill.• The round design also makes the cleaning process much easier and minimizes the fluid haul off. -Source: Pioneers 60 Series Rigs Limitation: These rigs are smaller but are still capable of drilling to a total depth of 13,000 feet.
GREEN COMPLETIONS• “Green” Completions can be dubbed as capturing methane during drilling completion and production (mostly in the flow back stream following hydraulic fracturing).• For this company must employ its midstream assets to lay a pipeline and flow wells back through a separator, thus removing the sand and water and capturing the remaining gas in a pipeline, rather than venting or flaring the gas.• Recently, Devon has been able to quantify a reduction of 13 billion cubic feet of emissions in the Barnett Shale area of North Texas by using green completions.
NOx Air Emissions Studies From well drilling; to fracking; to gas extraction, processing, and transmission, sources of air pollution emissions exist at every step in the process of converting unconventional gas into a marketable product. Air pollution sources from natural gas operations include:• vehicle emissions from construction equipment and diesel trucks hauling workers, drilling equipment, frack water, and waste water; Solved by Central Fracturing, Pad Drilling• diesel engines used to power drilling rigs and fracking pumps; Using Alternative Sources• large natural gas-fired stationary engines used to compress natural gas for pipeline transport;• emissions of raw natural gas to the atmosphere during well completion and from leaking pipes, valves, storage tanks, and processing equipment; Solved by CTD to some extent• volatilization from open wastewater pits. Solved by water management techniques
Development of Ultra-deep Drilling Simulator Ultra Deep Drilling Simulator Laboratories Modeling Rock Fluid Rock Mechanics Drilling fluids
Innovative Water Management TechniquesObjectives under this techniques:• Evaluation of promising commercially-available technologies for water reuse;• Development of novel coatings to improve performance and cost of ultra filtration, nano filtration and reverse osmosis treatment technologies in the demineralization of flow back waters;• Development of electro dialysis reversal for low-cost produced water and flow back water demineralization; and• Identification and evaluation of alternate sources of water that may be useful as replacements for groundwater or surface waters that serve as community water supplies.
• Oil shale produced waters are typically derived from retorting, mine drainage, and leachate from spent oil shale because of the methods used for extracting hydrocarbons from shale.• Waters generated from oil shale can contain many of the same constituents of concern (e.g. metals, arsenic, selenium, organics, and chlorides) present in other produced waters.• Simple treatment options include: ion exchange, reverse osmosis, electro dialysis reversal, mechanical evaporation. Limitation: High Cost Cost could be retrieved from improved efficiencies
Solution: Constructed Wetland SystemsMust include centralized facilities (pipe or haul to the location and treat) or decentralized facilities designed for a single well or for a few nearby wells. Even portable or “package” constructed wetland treatment systems can be designed to be pulled to a site by truck and capable of immediately treating water after set up. These “ready-to-go” systems could be very useful during fracture stimulation or high initial water production from unconventional gas wells.
• The components of a cell (hydrosoil, vegetation, and hydroperiod, in effect the residence time) are selected to produce conditions that promote specific biogeochemical treatment processes.• Hydrosoil (planting medium) contains sand, clay, and organic matter with proportions dependent upon desired conditions.• Examples of vegetation include Schoenoplectus californicus or bulrush when reducing conditions are needed and Typha latifolia (cattail) to promote oxidizing conditions. Hydroperiod is managed initially for rapid plant growth and then to sustain treatment performance.• The length of wetland cells in typical full-scale constructed wetlands ranges from a few m to over 100 m.
Impact of Constructed Wetlands• Reduces Environmental Risks• have the potential to be used for a variety of purposes, such as irrigation, livestock watering, cooling-tower water, municipal water use, domestic use, discharge to receiving aquatic systems for other use downstream, and support of critical aquatic life and wildlife.• This can allow continued operation of existing wells in mature fields with high water cuts and also lead to increased drilling and production, increasing the contribution of domestic energy resources to our national energy supply.
Combination of all aspects of EFD’s- EFD Scorecard• A scorecard must be developed to measure the tradeoffs associated with implementing low impact drilling technology in environmentally sensitive areas.• The scorecard must assess drilling operations and technologies with respect to air, site, water, waste management, biodiversity and societal issues.• The scorecard must address issues like1. getting materials to and from the rig site (site access)2. reducing the rig site area3. using alternative drilling rig power management systems4. adopting waste management at the rig site.
Participants in development of Scorecard Academia Environmental Industry Government OrganizationsSample EFD Scorecard
Eco-Centre Waste Management Facility• This waste processing center provides an unparalleled level of environmental compliance from the rig to final disposal which includes remote monitoring capabilities, allowing companies online access to track their waste streams and ensure environmental reporting compliance.• The 30,000-square-foot Eco-Centre facility can process in excess of 30,000 tonnes (33,000 tons) of drill cuttings and 14,000 cubic meters (3.7 million gallons) of liquid waste, or slops, annually.• The facility segregates each company’s drill cuttings, creating a transparent and fully auditable trail.• This facility provides E&P companies 24/7 visibility of their waste streams throughout the process.
• Eco-Centre facility aims to recycle and reuse the generated waste streams to reduce the overall carbon footprint of the facility and the operators it serves.• The “cleaned” solid materials are used in place of quarried aggregates to cap local landfill sites.• The recovered oil is reused to fuel the processing mill at the Eco-Centre while recovered water is used to cool and rehydrate the recovered solids.• To minimize use of local water resources, rainwater is captured and used for a variety of purposes, including fire suppression.
Efficiencies of Traditional Wells Stages of Efficiencies Pursuing for an E&P firm Efficiencies in Pursuing finding and Efficiencies in Development Water Costs Treatment and Pursuing Disposal Efficiencies in Production Operations As these stages are cumulated we get Pursuing more benefits Efficiencies in well drilling and completion
• Efficiencies in drilling can be improved by using the techniques discussed in EFD’s. Companies are now contracting for “fit for purpose” rigs and equipments to reduce drilling days.• Formation of Cross functional teams to maximize the production from wells operating in the basin. By investing $15 million in installing new pumping units and compressors, changing tubing sizes and performing well work over, production from these unconventional wells can be increased by 20%. Source: William Cos.
What are “fit for purpose” rigs and equipments?
• Efficiencies in Water Treatment and Disposal can be increased using Electro dialysis to separate desalted water from concentrated saline solution other than reverse osmosis, etc. Recently it has been have shown that CBM produced water could be treated for $0.15/bbl
• Efforts to reduce F&D costs must be initiated.• Also focus must be put on reducing drilling, simulation costs along with increased well recoveries.• This will help in increasing efficiencies in finding and Development Costs.
CONCLUSIONS• In this presentation, we tried to follow a balanced strategy which addresses almost all issues that appeared significant to us.• The techniques suggested can be combined together depending on geographical location and economies of various rigs.• Basically, we have prioritized increase in efficiency of each operation keeping in mind the environmental implication.