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Abstract Fracture growth in layered formations with depth-dependent properties has been a topic of interest amongst researchers because of its critical influence on well performance. This paper revisits some of the existing height-growth models and discusses the evaluation process of a new and modified model developed after incorporating additional constraints.The net-pressure is the primary driver behind fracture propagation and the pressure distribution in the fracture plays an important role in vertical propagation, as it supplies the necessary energy for fracture advancement in the presence of opposing forces. The workflow adopted for this study included developing a preliminary model that solves a system of non-linear equations iteratively to arrive at fracture height versus net pressure mapping. The theoretical results were then compared to those available in the literature. The solution set was then extended to a 100-layer model after incorporating additional constraints using superposition techniques.The predicted outcomes were finally compared to the fracture height observations made in the field on several treatments. A reasonable agreement between model-predicted and observed height was observed when a comparison between the two was made, for most cases.The majority of these treatments were pumped in vertical wells, at low injection rates of up to 8.0 bbl/min (0.021 m/s) where net pressures were intentionally restricted to 250 psi (1.72 MPa) in order to prevent fracture rotation to the horizontal plane.The leak-off was minimal given the low permeability formations. In some cases, however, the pumping parameters and fluid imparted pressure distribution appeared to dominate. Overall, it was apparent that for a slowly advancing fracture front, which is the case in low injection rate treatments, the fracture height could be predicted with reasonable accuracy. This condition could also be met in high rate treatments pumped down multiple perforation clusters such as in horizontal wells, though fracture-height measurement may not be as straightforward as in vertical wells. The model developed under the current study is suitable for vertical wells where fracture treatments are pumped at low injection rates. The solid-mechanics solution that is presented here is independent of pumping parameters and can be readily implemented to assist in selection of critical design parameters prior to the job, with a wide range of applicability worldwide.
Gondalia, Ravi Ramniklal (Schlumberger) | Sharma, Amit (Schlumberger) | Shende, Abhishek (Schlumberger) | Jha, Amay Kumar (Schlumberger) | Choudhary, Dinesh (Schlumberger) | Gupta, Vaibhav (Schlumberger) | Shetty, Varun (Schlumberger) | Bordeori, Krishna (Schlumberger) | Barua, Bhaswati Gohain (Schlumberger) | Singh, Mukund Murari (Schlumberger) | Zacharia, Joseph (Schlumberger) | Patil, Jayesh (Joshi Technologies International) | Murthy, P V (Oil and Natural Gas Corporation) | Das, Santanu (Oil and Natural Gas Corporation) | Mahawar, Dheeraj (Oil and Natural Gas Corporation)
Abstract From 2005 to 2020, the application of hydraulic fracturing technology in India has touched the length and breadth of the country in almost every basin and reservoir section. The variety of reservoirs and operating environment present in India governed this evolution over the past 15 years resulting in a different fit for purpose fracturing strategy for each basin varying from conventional single-stage fracturing (urban, desert & remote forested regions) to high volume multi-stage fracturing, deepwater frac-packs and offshore ultra-HPHT fracturing. The objective of this paper is to present the milestones along this evolution journey for hydraulic fracturing treatments in India from 2005 to 2020. This paper begins with a review of published industry literature from 2005 to 2020 categorized by reservoir type and the proven economical techno-operational fracturing strategy adopted during that period. The milestones are covered chronologically since the success or failure of technology application in one basin often influenced the adoption of novel hydraulic fracturing methods in other basins or by other operators during the initial years. The offshore evolution is branched between the west and the east coasts which have distinctly different journeys and challenges. The onshore evolution is split into 5 categories: Cambay onshore Barmer Hills & Tight Gas East India CBM and shale gas Assam-Arakan Basin Onshore KG Basin Each of these regions is at different stages of evolution. The Barmer region is in the most advanced state of evolution with frac factories in place while the Assam-Arakan Basin is in a relatively nascent stage. Figure 1 presents estimated hydraulic stage count based on published literature underlining the exponential growth in hydraulic fracturing activity in India. This paper enlists the technical and operational challenges present in the onshore and offshore categories mentioned above along with the identified novel techno-operational strategies which have proven to be successful for various operators in India. A comparison is presented of the different timelines of the exploration-appraisal-development journey for each region based on the economic viability of fracturing solutions available today in the Industry. Lastly, specific non-technical challenges related to available infrastructure, logistics and social governance are discussed for each region. This paper concludes by identifying the next step-change in the evolution of hydraulic fracturing operations in India among the 5 categories. Each of Government, operators and service providers have important roles to play in expanding the adoption of this technology in India. These roles are discussed for each identified category with the perspective of continuing the country's journey towards energy security.
Selladurai, Jagaan (Petronas Carigali Sdn Bhd) | Roh, Cheol Hwan (Petronas Carigali Sdn Bhd) | Zeidan, Amr (Petronas Carigali Sdn Bhd) | Anand, Saurabh (Petronas Carigali Sdn Bhd) | Madon, Bahrom (Petronas Carigali Sdn Bhd) | Akbar Ali, Anwar Husen (Petronas Carigali Sdn Bhd) | Motaei, Eghbal (Petronas Carigali Sdn Bhd) | Murugesu, Thanapala Singam (Petronas Carigali Sdn Bhd) | Othman, M. Nizar (Petronas Carigali Sdn Bhd) | Ismail, M. Izuddin (Petronas Carigali Sdn Bhd) | Zain, Siti Nur (Petronas Carigali Sdn Bhd) | Zamani, Nur Hidayah (Petronas Carigali Sdn Bhd) | Bela, Sunanda Magna (Petronas Carigali Sdn Bhd)
Abstract Malaysian clastic reservoirs are plagued with high fines content which rapidly deteriorates the productivity from wells completed with conventional form of sand control techniques. To mitigate the fines production issue, Petronas recently successfully completed 3 reservoirs in two wells in Field-D using enhanced gravel pack technique. This paper explains in detail the workflow, challenges such as depleted reservoirs, coal streaks, and nearby water contacts and operational execution for the successful re-defined extension pack jobs. This new approach consists of a re-defined Extension Pack / Frac Pack job with fine movement control resin and a re-defined perforation strategy. Perforation strategy consists of limited number of 180 deg phasing non-oriented perforations done under dynamic underbalance conditions. The key requirement to have fracturing as a sand control method is to have a tip screen out (TSO) or high net pressure placement to ensure the fracture has good conductivity. To obtain a good TSO, data acquisition is of paramount importance. The fracturing jobs in the Field – D wells were preceded with step-rate tests, injection tests, minifrac and Diagnostic Fracture Injection Test (DFIT). The data from diagnostic tests were used diligently to have best possible fracturing treatment in the target zones. Excellent pack factors of greater than 500 lbs. per ft were obtained for all the treatment jobs using only linear gel with proppant concentration up to 7 ppa. This high pack factor translates to very good frac conductivity which is essential in fracturing for sand control. Some of the fracturing treatments concluded with a TSO signature which is a big achievement considering the challenges that were associated with fracturing in Field – D. In addition, DFIT and ACA (After Closure Analysis) was performed to estimate permeability and results were compared with various techniques such as log derived and formation tester permeability. Ultimate objective from this analysis is to have a work-flow which can screen candidate wells for such treatments from openhole logs and give an estimated liquid rate post treatment. Also, the workflow for planning and executing fracturing jobs will be presented for Malaysian clastic reservoirs. This work-flow will be vetted against the extensive diagnostic and fracturing data that has been acquired during fracturing treatments in Field – D. Design, actual diagnostic, and fracturing data will be presented in this paper. It is expected that this modified form of sand and fines control will help in reducing the fines issue in Field – D to a great extent along with expected incremental in oil production. If long term production sustainability is proven, similar approach will be adopted by Petronas and can be shared amongst other South East Asia operators in many similar other fields.
Over the last 40 years, the Campos Basin has been a major stage for technology development to push offshore oil and gas production to water depths (WDs) never before experienced. This paper presents a retrospective of the most-significant technologies developed and deployed in the Campos Basin for more than 80 production systems in more than 30 oil- and gas-field developments; a few of these milestones are described in this synopsis. The discovery of oil in the Campos Basin in 1974 occurred in the context of the 1973 world oil crisis and its effects on geopolitics and the global economy. In addition to the challenges associated with this period, a need existed to increase oil production while reducing costs, leading to a fast-track approach. The development of the Garoupa field, followed by the Pargo, Badejo, Namorado, Enchova, Bonito, and Pampo fields, revealed huge oil-production potential, minimizing Brazil's need to import petroleum.
On occasion, there is a tendency to equate new advances in automation and intelligent systems with an inevitable workforce reduction, to an extent that people can begin to resist their application. However, as we all know from our own oilfield experiences, intelligent systems require well-prepared and creative engineers to deliver a successful and economic outcome and a synergetic relationship enhances the business and opportunity set as a whole. These technology advances offer a newer dimension to those options for qualified engineers to select, develop, and apply effective applications to ever-more-complex issues. As the resources that the industry develops become increasingly challenging, access to a broader range of options and new and developing approaches allows more- efficient and -effective recovery. This month, I have selected a suite of papers that considers intelligent systems, all clearly demonstrating that these approaches are becoming increasingly mainstream in their selection and use.
During the design, implementation, and operation of the Cascade and Chinook (C&C) field development project in ultradeep water in the Lower Tertiary play of the Gulf of Mexico (GOM), the technical limits of single-trip multizone (STMZ) frac-pack systems were pushed to depths greater than 27,000 ft using high fracture rates and high-strength proppants; knowledge was gained from ultrahigh-pressure (greater than 20,000 psi) tubing-conveyed perforating systems; and well-design criteria suitable for high-drawdown (more than 12,000 psi) production operations were demonstrated. The C&C development plan in the GOM is one of the most technologically challenging and complex projects ever implemented by Petrobras. This project uses the first floating production, storage, and offloading vessel in operation in US waters at a water depth of 8,200 ft. The C&C subsea infrastructure considers the use of subsea manifolds, rigid flowlines, pipe-in-pipe pipelines, and free-standing hybrid risers. These two fields are 15 miles apart and share several characteristics such as depth, lithology, and reservoir similarities.
This technical paper describes the planning and execution of a multiservice-vessel (MSV) -based hydraulic-intervention campaign in Chevron's Tahiti field in the US Gulf of Mexico. The five-well campaign was executed incident-free during 2015, delivering a total treatment volume of almost 30,000 bbl, resulting in 8,500‑BOPD gross initial production uplift and cost savings of 85% in comparison with traditional rig-based methods. The Tahiti reservoirs comprise stacked turbidite sandstone deposits. The three major reservoirs are M-XX, M-YY, and M-ZZ, which account for approximately 82, 9, and 9% of proved reserves in the field, respectively. The M-XX reservoir, of which all intervention candidate wells are a subset, is further separated into two distinct pay intervals, the M-XXA and the M-XXB.
A 2-year comprehensive effort to design, test, manufacture, and deploy a new high-pressure completion tubular (CT) for Chevron's deepwater Gulf of Mexico (GOM) operations is presented. The completion application expected harsh, aggressive loading modes and high pressures to be encountered. The major challenge was to design, test, and manufacture a subsea-completion string that would provide efficient hydraulics during fracturing operations while ensuring mechanical and pressure integrity. In 2004, the first built-for-purpose CT incorporating a gas-tight, rotary-shouldered connection was developed and deployed in the GOM. Since that time, rotary-shouldered connections have evolved (this evolution is described in detail in the complete paper).
Offshore subsea tiebacks to existing deepwater infrastructure can provide a profitable opportunity for operators in the US Gulf of Mexico (GOM) that are currently navigating a volatile oil price environment. Capital-intensive greenfield projects have been put on hold the past 3 years of this downturn throughout the industry. Speaking at a presentation hosted by the SPE Gulf Coast Section Reservoir Study Group, Anadarko General Manager Mike Ferfon said that the industry must be prepared to profitably work in an oil market of $40 to $60/bbl for some time out into the future. Focusing on a hub-and-spoke philosophy has allowed his company to leverage existing infrastructure and enable short-cycle, less capital-intensive subsea tieback projects in the GOM. Ferfon said one of the problems with deepwater projects is the slow pace of cost structure reconciliation with market pricing during a downturn.