Vijay, Rachit (Cairn Oil and Gas,Vedanta Ltd) | Panigrahi, Nishant (Cairn Oil and Gas,Vedanta Ltd) | Khanna, Manu (Cairn Oil and Gas,Vedanta Ltd) | Kothiyal, Manish Dutt (Cairn Oil and Gas,Vedanta Ltd) | Sarma, P J (Cairn Oil and Gas,Vedanta Ltd) | Bohra, Avinash (Cairn Oil and Gas,Vedanta Ltd) | Tiwari, Shobhit (Cairn Oil and Gas,Vedanta Ltd) | Pinto, Thomas (Welltec)
The subject well is a recently drilled and completed in Cambay field offshore in West coast of India. After landing the completion, two mechanical plugs were installed to nipple down BOP and nipple up X-mas tree. The plugs were installed in a 3.875" tubing hanger profile and in a 3.813" SC-TRSSSV selective profile. The problem arose while retrieving the 3.813" selective plug with 4" GS tool after installation of X-mas tree. The slickline wire snapped while doing the jarring operations resulting in fish in the well with BHA and plug slipping down below the selective profile. The plug fell inside the well and got stuck at the 4.5" × 3.5" tubing crossover joint ~20m below the SC-TRSSSV depth. The fished slickline wire along with the slickline tool-string BHA was successfully retrieved from the well, however, the plug remained stuck at the 4.5" × 3.5" tubing cross-over and could not be fished out even after several conventional approaches with slickline.
Solutions involving rig based retrieval and rig less coil tubing intervention and e-line robotic technology for retrieval of the plug were evaluated. Upon completion of a detailed feasibility study of available options, it was decided to conduct fishing of the plug with e-line based advanced robotic well intervention techniques such as eline miller, tractor and stroker. Unique milling bits were designed and customized for this operation. The milling operation involved multiple runs to target the removal of various parts of the struck lock mandrel. Upon successful milling operation, it was planned to retrieve the plug with slickline.
Initial attempts to retrieve the plug by straight pull using 33k pulling capacity Eline Stroker were unsuccessful. Subsequently, milling was attempted with a combination of E-line tractor and Miller to drill thru the plug. The milling initially started as per the plan but after 3 inches of milling the bit got stalled and was eventually stuck inside the plug. The E-line BHA had to be released from the mechanical disconnect sub above the bit. A modified 2" UPT tool with E-line tractor-stroker was run to fish out the bit and plug which resulted in the plug getting released from the stuck position and moving upwards about 10-meter from the stuck depth. Once this was accomplished, plug and bit were successfully retrieved with slickline.
The paper details the background of the stuck incident, selection methodology of fishing technique, fishing work plan and its successful execution. The paper also describes the operational difficulties encountered and the mitigation chosen while milling a plug with an electric line in the offshore environment.
Cambay Basin is one of the most prolific basin in India and categorized as proven basin. Hydrocarbon exploration in this basin goes back to 1958 and since then persistent geoscientific search has led to more than 79 oil and gas field discoveries. Around 2318 exploratory wells have been drilled till date in 244 prospects, out of which 97 are oil and gas bearing with nearly 40% success rate. Almost all the major structural features in the basin have already been drilled and the days of easy oil has gone. Consequently, with the advancement of technology, the exploration interest has been shifted to identify undrilled strati-structural traps. But locating these strati-structural traps and characterized the reservoirs remained a challenging task.
In this paper, I will discuss an integrated approach of identification of strati-structural traps and reservoir characterization with a case study from Cambay Basin. The study area is located in the southern flank of Sanand structure where hydrocarbon accumulation has been established in Kalol, Cambay Shale, and Olpad Formations. In this study area post rift Kalol Formations are conformable. Post depositional strike slip activity formed a flower structure and is a favourable hydrocarbon habitat within younger Kalol deposits. The 3D seismic attribute study indicates a channel feature within younger Kalol Formation. A coarsening upward sequence is observed in some wells above Kalol coal layers. Regional sand deposition models and the integrated study indicate that the sands in this area are mainly reworked tidal sands and were deposited over the highs and flanks through winnowing actions which holds the hydrocarbon.
This integrated approach greatly helps in identifying sand distribution pattern, facies category and reservoir properties to establish the remaining potential.
Presentation Date: Wednesday, October 17, 2018
Start Time: 1:50:00 PM
Location: 209A (Anaheim Convention Center)
Presentation Type: Oral
Padra Field, located in the eastern margin of south Cambay Basin, India is known for oil and gas production from unconventional fractured basaltic Deccan Trap. Earlier studies of Padra Trap showed moderately weathered basalt as the reservoir rock. However a thorough study integrating core and high resolution image log for characterizing the volcanic reservoir was yet to be ventured. Fracture modeling on PETREL™ platform was attempted using point data from wells and the resultant model was found to be in agreement with production data from wells. Difficulties faced during fracture coding based on FMI™ data owing to highly scattered fracture dip azimuths necessitated the present study to integrate FMI™ with core data.
As energy demand continues to grow, it is amazing that more than half of world oil production comes from fields as old as 30 years. The Cambay offshore fields off the coast of Gujarat, India started producing gas in 2002 and oil 2005. The production of Oil was possible through geophysical studies that led to incremental recoverable volumes. The oil wells with cased hole perforated completions however have a sanding problem after a few years of production leading to rapid oil production decline in the field as well as associated sand production issues.
This paper presents the result from implementing the simultaneous gravel packing and hydraulic fracturing of a well commonly known as “FracPacks” in the industry on a sanding well in the field and a comparison to 2 other wells with different completion techniques. The paper outlines the challenges faced with data collection, the design methodology, an overview of operations and execution. The outcome of the FracPack treatment was a textbook tip screen out placement leading to a 76% increase in oil production with zero water cut and sand. The results demonstrate the benefits of contacting the reservoir beyond the critical matrix even in a 2.4 Darcy formation and highlights that FracPacks can be less sensitive to the procedures used for wellbore preparations..
The lessons learned from the Cambay experience add to the growing number of case histories which show that FracPacks are effective techniques for sand management in high permeability formations. FrackPack performance is compared to other techniques such as standalone screens and gravel packs, both in terms of production as well as production longevity. This study will highlight the importance of selecting the completion technique based on the reservoir challenges and the importance of considering constraints such as nearby water, logistics and other operational concerns.
The first of its kind horizontal 'proof of concept' well, in India, Cambay-76 was drilled into the Late Eocene tight hydrocarbon reservoir of the Cambay Basin and completed with an Open Hole Multi-Stage (OHMS) swell packer completion. Drilling and completion operations were followed by another first of its kind in India, multi-stage hydraulic fracturing treatment of the Eocene EP-III/EP-IV zone. The hydraulic fracture jobs pumped the largest treatment fluid volumes in a well in India as well as placed the largest quantity of proppant in a single well in India. The application of horizontal well technology and multiple-stage hydraulic fracturing techniques has permitted the evaluation of "tight?? hydrocarbons. The OHMS is comprised of eight (8) water-activated swell packer stages with two (2) ball actuated fracture ports per stage, totalling 16 fracture initiation points. Tests conducted on selected core samples from an offset well provided basic rock properties and rock mechanical properties that were used in the fracture design and planning. After closure analysis (ACA), following a minifrac, provided reservoir properties to aid in production forecast. Microseismic monitoring was employed during all fracture treatment phases and provided data to determine the fracture geometry. Information
This paper describes the lessons leant in the development of a tight hydrocarbon reservoir and demonstrates that the "proof of concept?? can be scaled up across unconventional reservoirs in India. Extensive laboratory studies using formation cores and Microseismic monitoring results are also presented.
Farooqui, M.Y. (Gujarat State Petroleum Corp.) | Ghosh, Ujjal (Gujarat State Petroleum Corp.) | Ray, Arijit (GSPC) | Gupta, Sourabh Datta (Gujarat State Petroleum Corp) | Sarkar, Debjani (Gujarat State Petroleum Corp) | Ghosh, Priyam (Schlumberger) | Srigiriraju, Ramachandra (Schlumberger) | Sagar, Rajiv (Schlumberger) | Srivastva, Chandramani (Schlumberger) | Bhadra, Sutapa (Schlumberger) | Natarajan, Karthik Kumar (Schlumberger) | Agarwal, Gunja (Schlumberger) | Rao, Dhiresh Govind (Schlumberger) | Carrillat, Alexis
The natural gas industry is a relatively new entrant in the Indian energy sector, it is on the verge of making significant contribution to the Indian economy and is expected to significantly contribute to reduce Gross Domestic Product - energy elasticity coefficient.
The seven fold increase in natural gas reserves during last twelve years have generated an optimism for future gas discoveries in Indian sedimentary basins. The natural gas production is expected to increase nearly five folds by the turn of century from the present level of eight billion cubic meter per annum. In this paper, an attempt has been made to determine an appropriate pattern for optimal utilization of these large potentials of natural gas resources.
Presently, the priority use of gas, is considered as feedstock in fertilizer sector. The relative scarcity of commercial fuels coupled with the burgeoning energy demand have paved the way for natural gas utilization in other sectors. Systematic analysis has been carried out to determine the competitiveness of natural gas vis-a-vis other fuels/feedstocks in different sectors, taking into account, their historical growth trend.
The analysis indicate about eight fold increase in the deficit of power by the turn of the century which can be economically and efficiently narrowed by the gas based power plants. The major portion of petroleum demand in transport and domestic sectors presently met by import of middle distillates, may be substantially supplemented by natural gas, in future. Case studies for fuel replacement by gas, in these sectors, have also been discussed.
The integrated national development is expostulated by the development, distribution ana diversification of natural gas through a 'National Gas Grid'.
During the last two decades the world energy scenario has witnessed intense consciousness of energy related problems, emergence of new energy imperatives and realization of stellar role that natural gas is poised to play in forthcoming years. Natural gas currently meets about one fifth of the global commercial energy requirements, predominantly because of the large scale use in developed countries.
The emergence of natural gas as energy transition option has far reaching ramifications, particularly, for petroleum deficient developing nations. The historical development of gas industry in developed countries epitomizes the opportunities and challenges that lie before the developing countries. An analytical examination of growth of gas industry delineates the following five phases of development in the western world:
1. Marketing of gas to small industrial and agricultural consumers in the vicinity of gas finds.
2. Growth of gas reserves and replacement of small users by large industrial and power consumers.
3. Development of distantly located gas market construction of transmission and distribution network and supply to domestic sector.
4. Diversification of natural gas to other industries.
5. Steady share of gas in total energy scenario.