This paper reviews existing analysis of well integrity related regulation in upstream unconventional oil and gas projects and proposes a methodology to enhance such regulation in the future. This paper has compiled findings from a number of peer-reviewed sources assessing regulatory systems across a number of jurisdictions. These findings were based around four key questions that this paper has assessed (1) what is the overall assessment of current regulatory systems; (2) where to-date are the key areas that current research have focused on; (3) what are the key strengths identified in current research; and (4) what are the key gaps in current research?
This paper demonstrates that the body of work provides a wide array of assessments and conclusions. Whilst some are quite explicit in their judgment of a particular system’s effectiveness, many refrain from making a holistic assessment in a particular jurisdiction. Much of the research involves the application of prisms, such as environmental risks or local government jurisprudence. Along with these prisms, a number of common aspects of research are identified that strengthen the analyses, such as the use of ‘as drilled’ data and the use of relevant data samples. Some research gaps remain despite these strengths.
The majority of previous researchers can identify some degree of ineffectiveness in various regulatory regimes. Further, a number of gaps exist as a result of regulatory systems being incomplete or inadequate, potentially masking other inadequacies. To address these gaps, this paper proposes a methodology to improve and clarify knowledge and practical recommendations to improve the effectiveness of assurance activities by both regulatory agencies and operators. Specifically, this methodology focuses on a typological assessment of written rules in a number of jurisdictions. As an example, we present an ‘as built’ dataset to assess compliance with rules and identify means of assurance. This methodology proposes surveying of regulatory agencies and operators to validate the assertion that gaps can be identified and corrected and provide more insight into how regulatory systems function and the systematic causes of gaps.
Fu, Xuebing (Goolsby Finley & Associates) | Bonifas, Paul (Goolsby Finley & Associates) | Finley, Andy (Goolsby Finley & Associates) | Lemaster, Julia (Goolsby Finley & Associates) | He, Zhiyong (ZetaWare, Inc) | Venepalli, Kiran (CMG Inc.)
Over the last decade, tight oil production has become significant with the success of horizontal drilling and hydraulic fracturing. However, the recovery factor of tight oil production remains very low and no standard secondary recovery method exists after primary depletion. We propose a new secondary recovery method: to use existing hydraulic fractures (every other fracture) in a horizontal well as gas injection and oil production sites to conduct
An ideal process of this method envisions a horizontal well centered in an enclosed reservoir, where the hydraulic fractures are evenly distributed along the well, parallel to each other. If the hydraulic fractures can be effectively isolated, and injection and production can be conducted through alternate fractures at the wellbore, then highly efficient flooding patterns can be created. Key questions include: Is there adequate injectivity and productivity in a sub-microdarcy reservoir? How far are the ideal reservoir conditions from reality? How difficult is it to isolate individual fractures within the wellbore?
Is there adequate injectivity and productivity in a sub-microdarcy reservoir?
How far are the ideal reservoir conditions from reality?
How difficult is it to isolate individual fractures within the wellbore?
In addressing these key questions, first, the success of a flooding process relies on reasonable injectivity and response time between the injector and producer – in this case the injector being one hydraulic fracture and the producer being an adjacent hydraulic fracture; both economical rates and reasonable communication time between adjacent fractures are demonstrated through analytical calculations and reservoir simulations in a typical well setting; nearly 100% recovery is achieved in the reservoir units between the fractures in a miscible flooding process. Second, actual reservoir conditions are incorporated in our study, focusing on direct fracture communications; the effects are demonstrated, and comparisons among different methods are made. Finally, potential challenges in operations are summarized and current technologies are reviewed; the gaps between the current settings and the required settings are demonstrated. Economic discussions are made, indicating positive scenarios with large tolerances.
With the rapid development of tight oil reservoirs, Enhanced Oil Recovery (EOR) technologies are urgently required to improve the recovery factor beyond primary depletion. An effective flooding process may be conducted if the hydraulic fractures can be used as injection and production ports. As a first attempt to envision an inter-fracture flooding process, key aspects are defined and examined, showing promising results. Inter-fracture gas flooding may become a standard secondary recovery technique for tight oil reservoirs and add significant reserves.
Potapenko, Dmitriy (Schlumberger) | Theuveny, Bertrand (Schlumberger) | Williams, Ryan (Schlumberger) | Moncada, Katharine (Schlumberger) | Campos, Mario (Schlumberger) | Spesivtsev, Pavel (Schlumberger) | Willberg, Dean (Schlumberger)
Highly efficient multi-stage hydraulic fractured horizontal wellbores are the dominant completion method for many basins worldwide. One potential weakness of multi-stage hydraulic fracturing is that the later stages of the completion workflow – frac-plug drill out (FPDO) and flowback – cause large pressure fluctuations and transient flows through the perforation clusters that coincide with a period of low closure stress in the fractures. The proppant packs in the fractures during this period are fragile and prone to failure. Previously reported results show that flowback and initial production practices have a major impact on proppant production, maintenance and disposal costs and the subsequent well performance. In this paper the results from over 200 FPDO and flowback operations from the United States and Argentina are reviewed. These results show that maintaining a balanced flowrate during FPDO operations is critical for minimizing inadvertent damage to the hydraulic fracture network.
The FPDO flowrate balance is the difference between the coiled tubing injection and annular return flowrates. The magnitude and sign of the balance corresponds to the instantaneous flowrate through the open perforation clusters into or out of the hydraulic fracture network. A positive balance rate, or overbalance, injects fluid into the fracture system. A negative balance rate, or underbalance, produces stimulation or formation fluids from the fracture network. Sudden changes between these two regimes creates local flows that can be severe enough to flush large quantities of proppant out of the fractures. Our results show that high-frequency multiphase flowmeters simplify the process of maintaining balance (no inflow, no outflow). Furthermore, close monitoring of any imbalance that develops, and rapid control of the surface choke and injection rate, can provide for an efficient operation while protecting the integrity of the fracture system.
Early monitoring of flowback and production with a high frequency flowmeter was shown to be extremely useful technique for optimizing well productivity during well clean-up. This paper also shows how a dual energy gamma ray multiphase flowmeter successfully quantified proppant produced during FPDO and flowback. Examples of the dynamics of sand production are shown, as well as correlations to events of excessive underbalance conditions.
At the end of the paper we show that most of the highlighted problems can be solved through making changes to the well construction workflow and accounting for relationships between various well operations. Incorporation of this workflow enables early prediction of well performance issues and their efficient resolution.
The Powder River Basin has emerged over the past year as the latest source of oil production growth for the Lower 48. Companies ranging from a reborn Samson Resources to US onshore mainstays Devon, Chesapeake, and EOG are now betting on the basin to become a long-term core asset. Colorado’s industry lacks the size, variety, and Wild West characteristics of Texas, but that is precisely why the Centennial State’s oil production is surging to record levels. This paper describes a comprehensive field study of eight horizontal wells deployed in the stacked Niobrara and Codell reservoirs in the Wattenberg Field (Denver-Julesburg Basin).
If you can see it, then maybe you can control it. This sums up the latest quest that the unconventional engineering community embarked upon to get a better understanding of proper well spacing and how fractures really interact. Devon Energy will be getting simpler and smaller by selling two no-growth assets—gas acreage in the Barnett Shale in Texas and oil sand operations in Canada. Its future is staked on growing oil production in the Permian’s Delaware Basin and three other unconventional oil plays. The struggle to overcome the challenge of frac hits has led to a critical dialogue about which pathway the shale sector should take.
Achieving high hydrocarbon recovery is challenging in unconventional tight and shale reservoirs. Although EOR/EGR processes could potentially improve the recovery factor beyond the primary depletion, large-scale field application of these processes are not yet established in these reservoirs. This session will focus on the latest research trends, modelling and experimental work to better understand issues involved in improved economic recovery from such reservoirs.
The shale sector is studying the results of a 23-well experiment in the southeastern corner of New Mexico to learn what the wider implications might be. Researchers from the Federal Reserve Bank of Dallas quantified the economic impact of the US shale revolution for the first half of this decade. The green light for Santos Energy’s drilling program in the McArthur Basin comes after a moratorium on hydraulic fracturing in the Northern Territory was lifted in 2018. Findings from Kayrros suggest the average Permian well is both less productive and more expensive than reflected in public data. Permian Basin operators and service companies met to discuss completions diagnostics, flowback strategies, water management, and artificial lift strategies.
Findings from Kayrros suggest the average Permian well is both less productive and more expensive than reflected in public data. The projects are designed to reduce technical risks in enhanced oil recovery and expand application of EOR methods in conventional and unconventional reservoirs. Twelve organizations—universities and private technology companies—will conduct research and development on emerging shale plays and technologies covering everything from digital pressure-sensing to smart microchip proppant. The evolution of hydraulic fracturing is a long and circuitous one that deserves examination. Engineering and completions leaders from Liberty Oilfield Services did just that, authoring a paper that encapsulates the high points in the development of the groundbreaking completions practice.
Australia’s BHP Billiton and the recently acquired Anadarko Petroleum submitted the largest dollar totals of high bids in US Gulf of Mexico Lease Sale 253. Oxy has won the fight for Anadarko. Citing capital discipline as the reason, Chevron has elected not to make another bid for the independent. Anadarko Petroleum now plans to exit its agreement with Chevron after deeming Occidental Petroleum's revised takeover bid "superior." Colorado voters soundly defeated a measure 6 November that would have restricted the vast majority of new development in the country’s fifth largest oil-producing state.
Researchers from the Federal Reserve Bank of Dallas quantified the economic impact of the US shale revolution for the first half of this decade. Production from the Hibernia platform was shut down again on 17 August after its second oil spill in a month, while Husky Energy began to ramp up output from the White Rose field following the largest-ever spill off Canada’s easternmost province. Anchored by the Khaleesi-Mormont and Samurai fields, the King’s Quay FPS will receive and process up to 80,000 B/D of crude oil. Despite reports to the contrary, Permian well productivity remains healthy, with average new production per well in the basin matching all-time highs, Rystad says. Researchers mapped 251 faults in the North Texas home of the Barnett Shale, the birthplace of the shale revolution, finding that wastewater injection there “significantly increases the likelihood for faults to slip.”