This paper discusses the approach of Cairn Energy India Ltd. (CEIL) in the use of a state of the art technology that integrates all relevant data scenarios for designing and planning development wells in the Mangala field of Western Rajasthan, India.To improve the quality of the well planning process, CEIL has realized the importance of a collaborative well planning environment, which was implemented by means of its world-class 3D visualization center that enables multidisciplinary well planning workflows to take place in the subsurface environment. The environment includes physical infrastructure, new technology, and data. A fully functioning collaborative well planning environment enables the drilling team to plan wells using engineering tools, including drilling target definition and refinement, well pad positioning, and wellbore position uncertainty, based on company anti-collision policies, with geosciences team capacity to validate those designs against their subsurface data.The Mangala field development process has established the success of CEIL with rapid, multisolution iterations well planning to the entire asset team and improved wellbore positioning based on potential engineering constraints. This process takes the optimum reservoir drainage into account with possible geological hazards and reduces the operational cost by complementing technical expertise across the broad disciplines. The workflow aids wellbore and drilling optimization and improves decision making and collaboration throughout the field development sequence.The paper explains the detailed aspects of collaborative well planning and optimization of well placement methodology used for Mangala field, which includes 11 horizontal wells that were largely designed as shallow extended reach drilling (ERD) wells. It demonstrates how this method significantly improved the mutual workflow between departments and increased efficiency. This paper also describes the interactive design that dramatically decreased the cycle time in planning more than 160 wells in the field, which contributed to effective development plans and well placement based on geological, drilling, and completion requirements. IntroductionThe level of complexity and difficulty of performing planning phases has increased over the last two decades, especially in those cases that require collaboration among all disciplines, including drilling, geology, geophysics, and reservoir characterization. This process collectively demands the respective professionals to contribute their expertise in optimizing the well. The ability of each discipline to rapidly create and evaluate a mixture of alternative development plans and to efficiently make key decisions during the planning stage provides the most value to the overall development project.CEIL has deliberately worked toward improving its existing resources, including the people, facilities, hardware, and software services, because only with this new method of working will it revolutionize the way that people manage their day-to-day ass...

The 6"hole section in Raageshwari Field NW India (onshore) is typically between 600-800m long and highly challenging in terms of formation strength and abrasiveness. Lithology in the upper part is composed of sandstone, claystone and weathered basalt with unconfined compressive strength (UCS) between 3-5kpsi. The lower section contains basalt, felsic and sub-felsic igneous formations with UCS range of 15-30kpsi. Historically, a two bit strategy was employed. First, a PDC bit on a positive displacement motor (PDM) bottom hole assembly was used to drill the soft 6" section until ROP dropped to an unacceptable level. The BHA was then pulled and followed by a diamond impregnated bit on a turbine BHA to drill the very hard volcanics. Typical average on-bottom ROP for the entire section was 4.5m/hr and took approximately 170 hours to reach total depth (TD). To reduce costs, new technology was proposed to improve bit durability in the hard/abrasive volcanics and drill the entire 6" section in one run at a higher ROP. Recent bit and drilling data from offset wells was analyzed to assist in developing a new, cost effective PDC design to replace the expensive diamond-impregnated bits and drill the 6" hole section in one run. The study resulted in a new six-bladed PDC bit with 13mm cutters that incorporates superior cutter technology to improve durability and resist physical and thermal degradation. The design includes a row of backup cutters in the shoulder area to increase radial diamond volume for maximum durability. The new PDC bits have been run on a motor and rotary steerable bottom hole assemblies and drilled the 6" section on three consecutive wells in Raageshwari field totaling 2328meters with an average ROP of 10.7m/hr. This represents approx. 47% decrease in drilling time compared to that previously achieved by Impreg/TCI bit runs. Typically, the new bits are pulled in re-runable condition. This improved performance has saved the operator approximately six-days of rig time and approximately USD 480,000/well.

During exploration activities in the Thar Desert of Rajasthan, India, Cairn India Ltd. discovered numerous oil fields in the Barmer Basin. The oil reservoirs are relatively shallow and benign in terms of pressure, temperature and corrosivity, but they posed significant flow assurance challenges due to relatively high crude viscosity, wax content and pour point. As a result, surface facilities are reliant on heat for flow assurance. Total reliability of power and fuel supply for the facilities was essential to ensure export product quality and for flow assurance for the waxy oil. The paper presents Cairn’s approach of utilizing state-of-the-art technology that integrates all relevant data scenarios for the drilling and production systems for this lean gas condensate reservoir. This development will provide the necessary power and heating fuel supply and the primary gas supply for the main oil processing terminals and for power generation stations along a 600km heated export pipeline.through the end-of-life for the major oilfields discovered in Western Rajasthan, India. Raageshwari Deep wells target tight, predominantly volcanic reservoirs with cost-effective monobore designs that include multiple fracture stimulations in various pay zones to maximize well productivity. The slimhole well design, dynamic completion design, and careful bit design and selection successfully enabled the drilling of these wells with 26% cost savings on the total budget for drilling ten wells ($ 2M per well). A program highlight was the drilling of volcanic tuff formations in a single run. The paper will describe detail aspects of monobore well planning and well design implementation including fracture stimulations. It will also demonstrate how this significantly improved the well delivery that contributed to effective development plans for these major oilfields.

The 6"hole section in Raageshwari Field NW India (onshore) is typically between 600–800m long and highly challenging in terms of formation strength and abrasiveness. Lithology in the upper part is composed of sandstone, claystone and weathered basalt with unconfined compressive strength (UCS) between 3–5kpsi. The lower section contains basalt, felsic and sub-felsic igneous formations with UCS range of 15–30kpsi. Historically, a two bit strategy was employed. First, a PDC bit on a positive displacement motor (PDM) bottom hole assembly was used to drill the soft 6" section until ROP dropped to an unacceptable level. The BHA was then pulled and followed by a diamond impregnated bit on a turbine BHA to drill the very hard volcanics. Typical average on-bottom ROP for the entire section was 4.5m/hr and took approximately 170 hours to reach total depth (TD). To reduce costs, new technology was proposed to improve bit durability in the hard/abrasive volcanics and drill the entire 6" section in one run at a higher ROP. Recent bit and drilling data from offset wells was analyzed to assist in developing a new, cost effective PDC design to replace the expensive diamond-impregnated bits and drill the 6" hole section in one run. The study resulted in a new six-bladed PDC bit with 13 mm cutters that incorporates superior cutter technology to improve durability and resist physical and thermal degradation. The design includes a row of backup cutters in the shoulder area to increase radial diamond volume for maximum durability. The new PDC bits have been run on a motor and rotary steerable bottom hole assemblies and drilled the 6" section on three consecutive wells in Raageshwari field totaling 2328meters with an average ROP of 10.7m/hr. This represents approx. 47% decrease in drilling time compared to that previously achieved by Impreg/TCI bit runs. Typically, the new bits are pulled in re-runable condition. This improved performance has saved the operator approximately six-days of rig time and approximately USD 480,000/well.

During the exploration and appraisal phase in the RJ-ON-90/1 block, operated by Cairn Energy India in the Thar Desert of Rajasthan, India, the company discovered numerous oil fields in the Barmer Basin spread over a huge area. The emphasis was to develop these fields with significant savings in both land and infrastructure costs while minimizing environmental impacts. A compact rig design coupled with a multi-well pad concept was the chosen solution.The paper presents use of an innovative onshore pad drilling system which was implemented via a custom built Rapid Rig technology that allows fast, efficient drilling operations on multi-slot pads to enhance the success of the extensive drilling campaign for these oilfields.The rigs are highly mobile, skid mounted, electrically driven 1,000HP "Super singles". They were custom built in Houston for Cairn to deploy in Rajasthan for the drilling of more than 350 development wells. The Rapid Rig's small footprint and self deploying design allows for ease of transport and faster onsite rig-up. These rigs are the first of their kind with wheels attached to the base structure. Unlike conventional rigs, these purpose-built rigs move easily and quickly (4hrs) between pad slots without rigging down, which in turn cuts well construction time and delivers greater efficiency at reduced costs. The fully automated rig floor coupled with an innovative pipe handling system reduces crew size and accident exposure (zero pipe handling LTI's) while providing a more comfortable and efficient work environment, leading to a substantial reduction in well construction time (1,200-1,500m wells are drilled in 7 to 9 days). The paper will explain detailed aspects of the custom made Rapid Rig design and its implementation including the pad drilling concept. It will also demonstrate how this significantly improved the well delivery, contributing to substantial cost and well construction savings without compromising HSE standards.