Drilling Rigs and Well Technology RAPID RIGS AND WELL TECHNOLOGY.
2 3 Cairn India has adopted an innovative approach for its onshore drilling program using state-of-the-art custom made Rapid Rig technology in Mangala, Bhagyam and Aishwariya oilfields in western Rajasthan, India. To enhance the success of its onshore Rajasthan oilfield developments that involve drilling hundreds of wells over the long term, Cairn has applied the concept of pad drilling using custom built Rapid Rigs that allow fast and efficient drilling operations on multi-slot well pads. Well pad based development approach has eliminated the need for extensive land acquisition and reduces the surface pipelines network over the field. The well pads support multiple wells (up to 28 well slots) from a single location and better management of production & injection fluids. The wells being drilled are high production rate wells akin to offshore wells and the well heads, xmas trees Rig 807 at work on a Mangala well pad in Rajasthan and pipelines are landed inside cellars that are 5 m deep below the ground level to avoid the need to shut down wells during rig moves. This facilitates achieving maximum well uptimes and minimizes any interference with the existing production and injection wells on the pad. Two custom built highly mobile super single 1,000 hp, ac drive drilling rigs built in Houston, have been deployed in Rajasthan to drill more than 350 development wells. The rigs are the first of their kind with wheels attached to the base structure. Unlike conventional rigs, these purpose built rigs can move easily between the slots on the pad without rigging down, which in turn cuts well construction time and delivers greater productivity at reduced costs. The Rapid Rigs are highly mobile, skid mounted efficient super singles type drilling units with a 500,000 lbs hook load capacity for Rapid rig move in progress at Mangala well pad
4 5 Rapid rig and completion rig working simultaneously on well pad 9 shallow to moderate well depths. Smaller footprint and self deploying design of these rigs allows ease of transport and faster onsite rig-up. Typical rig move times are less than 10hrs from release to spud for slot-to-slot movement with the rig utility equipment kept stationary at one location on the pad with a long festoon connecting the rig with the power cables and other utility lines, leading to the well construction times being reduced (1200-1500 m wells with 2 casing strings are drilled in 5 to 8 days). The fully automated rig floor coupled with an innovative pipe handling system reduces crew size and accident exposure while providing a more comfortable, efficient work environment. The compact rig layout together with the well pad concept offers significant advantages in saving land & infrastructure costs, minimizes environmental impact and small-footprint. A completion & workover rig is also in operation in the Rajasthan oilfields. This rig is also a highly mobile mechanical self propelled (truck type carrier) 550 hp rig capable of working the string with 250,000lbs hook load. The self propelled feature of the rig is further complemented by a unique hydraulic jack-based skidding system. The substructure has been designed exclusively for Cairn s Rajasthan Operations with a skidding system that enables the rig to move from one slot to another using a hydraulic jack in just 2-3 hours without having the need to lower the mast. The rig has been packaged in such a way so as to reduce inter-pad movement time. The rig is capable of working on both multiwell pad locations and on independent locations. It has a provision to rack back pipe in the mast with finger slots to accommodate 3,500 m of R2 length 4-1/2 tubing in doubles. The rig has three mud tanks with a total of 900 bbls working capacity and a 500 HP triplex mud pump with 5,000 psi rated working pressure. Development wells being drilled in the Rajasthan Mangala field are both deviated and horizontal high deliverability wells designed for up to 10,000 bopd production. The first horizontal well has recently flowed Heat Tube over 11,500 bopd oil rate during test, which is a record onshore production rate in India. State-of-the-art drilling tools including geosteering, MWD/ LWD systems are being used to drill and place the horizontal laterals. Latest and innovative completion techniques are being deployed to complete the production wells to deal with sand production, flow assurance, emulsions, corrosion and scaling issues associated with production. Jet pumps and ESPs are planned to be installed to lift the medium and high flow rate wells respectively, as the water cut rises in the wells. Latest generation Inflow Control Devices (ICD) technology combined with sand control screens are being deployed to ensure uniform drainage across the horizontal sections and maximize recovery from the wells. Innovative use of heater strings downhole to circulate hot water in the production annulus of the wells and eliminate congealing and wax deposition in the tubing that could potentially cause well downtimes helps maintain high uptime on wells. Permanent downhole gauges are being installed in key wells to have continuous reservoir surveillance thereby facilitating efficient reservoir management practices. Specifically designed well heads are used to accommodate the complex completion including heater string, twin capillary injection lines, ESP cable or the data cable for permanent downhole gauges alongside the production tubing. Water injection wells which are the key for pressure maintenance and waterflooding of the reservoirs are designed as slim monobore type wells that are inherently cost effective. To date a total of +250 development wells have been drilled using the 2 rapid rigs to an average C Tyco depth Thermal of ~1500 Controls meters. W LLC A total of ~ 373,800 meters of new A hole has been drilled, logged and cased T at an E average rate of 156 meters per day R using the Rapid Rigs over a period of 3.5 yrs which is a record performance in the Indian oil industry. Drilling performance
6 7 is planned to be optimized further with continuous improvement plans in place. A hydraulic fracturing equipment spread with about 8000 HHP is currently operating in the field to hydro-frac low permeability, deep and tight volcanic gas reservoirs encountered in the area to produce gas needed to meet the fuel demand for the production facilities and the power stations along the export pipeline route. Slim monobore type well designs adopted for these gas wells allow stimulating multiple reservoirs intersected in each well in Mangala 8 & 9 wells completed and hooked up inside cellar a very cost effective manner. The well designs chosen also avoid the need for a service rig standing by to support the stimulation/intervention operations, thereby enhancing operational efficiencies significantly. Reservoir management and well servicing needs of the Rajasthan fields are actively supported by the completion & workover rig; slickline units ; hot oiling units; e-line units; and coiled tubing unit working across the fields on dedicated basis to produce the oilfields efficiently. High technology, high production rate wells Jet Pumps / Electrical Submersible Pumps for artificial lift Hot water is power fluid for Jet Pumps and flow assurance Heater String in production well Twin chemical injection lines to inject chemicals down hole Optimal metallurgy to prevent corrosion Unitized well head systems Monobore completions in injectors
RAPID RIGS AND WELL TECHNOLOGY CAIRN INDIA LIMITED Cairn India is one of the largest independent oil and gas exploration and production companies in India with a market capitalisation of ~ US$ 10 billion and the fastest-growing energy company in the world as adjudged by the Platts 2012 and 2013 Rankings. Cairn India operates more than 25 per cent of India s domestic crude oil production. Through its affiliates, Cairn India has been operating for more than 15 years playing an active role in developing India s oil and gas resources. To date, Cairn India has opened 4 frontier basins with over 40 discoveries, 28 in Rajasthan alone. The Mangala field in Barmer, Rajasthan, discovered in January 2004, is the largest onshore oil discovery in India in more than two decades. Mangala, Bhagyam and Aishwariya fields major discoveries in Rajasthan block have gross ultimate oil recovery of over 1 billion barrels from primary, secondary and enhanced oil recovery (EOR) methods. Cairn India has a portfolio of 9 blocks - one block in Rajasthan, two on the west coast and four on the east coast of India, and one each in Sri Lanka and South Africa. Oil and gas is currently being produced from Barmer, Ravva and Cambay. 3rd & 4th Floors, Vipul Plaza, Sun City, Sector 54, Gurgaon 122 002, India +91 124 459 3000. Follow us: Twitter - @Cairn_India LinkedIn - company/cairn-india-ltd YouTube - cairnindialtd SlideShare - cairnindia www.cairnindia.com