The initial high cost of exploitation of the sustained, increasingly growing development of unconventional resources in Argentina has resulted in concentrating all efforts to increase well productivity while reducing construction and completion costs. The optimization of hydraulic fracture (HF) treatments is vitally important. It is the primary strategy used to achieve an optimal reservoir drainage area, consequently characterizing the fracture geometry, including the height, for the continuous improvement of HF treatment and planning.
Several types of technologies and methodologies are used to estimate fracture height during and after a hydraulic stimulation treatment. These technologies can provide information about the fracture geometry and extension in the near-wellbore (NWB) and far-field areas. The determination of a reliable correlation between those methodologies represents a challenge as a result of formation complexity, heterogeneity, and limitations of evaluation technologies. It is well-known that some areas in the Vaca Muerta formation contain layers that can act as fracture barriers and are responsible for fracture containment.
This paper presents a fast and simple methodology that uses conventional well logs [gamma ray (GR), sonic, and density] from pilot wells to identify potential fracture barriers. This approach establishes a means to evaluate the degree to which the rock will have the ability to control fracture height growth. This methodology was determined useful for planning perforation intervals or clusters placement, particularly in those formations with stress profile showing reduced stress contrast and, when complemented with geological information, this method also provides useful information for horizontal well trajectory. Case studies are provided to illustrate examples of the proposed fracture barrier index (FBI) being calibrated or compared to other fracture height assessment. Additionally, the benefits of adding this new approach to current methodologies and technologies to aid completion design optimization and decision making is discussed.
Analytically-derived criteria are presented for the orientation of fracture initiation from horizontal wellbores drilled in porous-permeable (poroelastic) media. This involves drilling-induced tensile fractures (DITFs) from non-perforated wellbores and completion-induced hydraulic fractures (CIHFs) from perforated wellbores with cylindrical perforation geometry. The criteria are developed considering the tangential stresses on two points (extremes) around the base of the perforation; one for the initiation of longitudinal fractures and another for the initiation of transverse fractures, with respect to the wellbore. In-situ stress state, wellbore pressure, and the formation's mechanical and poroelastic properties are independent variables that are shown to control the orientation of the initiated hydraulic fractures; the dependent variable.
The DITF orientation can be used to constrain the magnitude of the maximum horizontal stress; the most difficult aspect of the in-situ stress tensor to constrain. Transverse CIHF initiation only occurs over a narrow wellbore pressure-at-breakdown window, while longitudinal initiation occurs at comparatively higher wellbore pressures. However, transverse CIHF initiation occurs more frequently than transverse DITFs, because the presence of perforations aids transverse fracture initiation. The region of the in-situ stress states where transverse initiation is promoted is shown in dimensionless plots for perforated and non-perforated wellbores. Fracture initiation criteria for specific cases presented can be used to predict the orientation of fracture initiation in oilfield operations.
The orientation of CIHFs controls the productivity of hydrocarbon reservoirs. Productivity from low permeability formations is greatly improved having multiple fractures oriented transversely rather than longitudinally, relative to a horizontal wellbore. Fracture initiation often follows a plane different to the final fracture propagation plane. Stress re-orientation in the near-wellbore region may promote fracture initiation of different orientation than the orientation dictated by the far-field stresses. The range of in-situ stress states in which transverse fracture initiation is promoted increases as Biot's poroelastic coefficient,
Data Analytics is progressively gaining traction as a viable resource to improve forecasts and reserve estimations in most prospective US shale plays. Part of those learnings has been tested for the reserves and resources estimation of the next worldwide top-class shale play, Vaca Muerta formation in Argentina. In this work, we rely on advanced artificial intelligence methods to automate workflows for production forecasting and reserve estimation in the Vaca Muerta formation. To achieve this goal, we develop a computational platform capable of integrating several sequential operations into a single automated workflow: (1) data gathering; (2) data preparation; (3) model fitting and forecasting and, (4) EUR estimation. As new data becomes available, each of these steps is performed automatically. The proposed platform also integrates with advanced business intelligence tools that aid at facilitating graphical interpretation and communication among specialists and decision makers. Hence, the suggested workflow can deliver production forecasts several magnitudes faster than traditional workflows while maintaining accurate and engineering sound results. Having fast and reliable forecast turnarounds allow for timely tracking key differences and commonalities among multiple shale plays to facilitate informed decision strategies in unconventional field evaluation and development.
Mahzari, Pedram (Department of Earth Sciences, University College London) | Oelkers, Eric (Department of Earth Sciences, University College London) | Mitchell, Thomas (Department of Earth Sciences, University College London) | Jones, Adrian (Department of Earth Sciences, University College London)
During the past decade, enhanced oil recovery (EOR) by CO2 in shale oils has received substantial attention. In shale oil reservoirs, CO2 diffusion into the resident oil has been considered as the dominant interaction between the CO2 in fractures and the oil in the matrices. CO2 diffusion will lead to oil swelling and improvement in oil viscosity. However, despite two-way mass transfer during CO2 EOR in conventional oil reservoirs, one-way mass transfer into shale oils saturated with live oils is controlled by an additional transport mechanism, which is the liberation of light oil components in the form of a gaseous new-phase. This
Taking account of Bakken shale oil reservoir data, numerical simulations were performed to identify efficiencies of EOR by CO2 at the laboratory and field scales. Equation of state parameters between CO2 and oil components were adjusted to optimize the calculations and a sensitivity analysis was performed to identify the role of gas formation and consequent EOR efficiencies. At the laboratory scale, in-situ gas formation can increase oil recovery by 20% depending on the amount of gas saturation. Also, the CO2 storage capacity of the shale matrix can be enhanced by 25%, due to CO2 trapping in the gas phase. At the field scale, an additional oil recovery of 9.1% could be attained, which is notably higher than previous studies where this gas evolution mechanism was ignored. Furthermore, the results suggest that a six-weeks huff period would be sufficient to achieve substantial EOR if this new mechanism is incorporated. On the other hand, the produced fluid in the early period was primarily composed of CO2, which would make it available for subsequent cycles. The produced gas of the well under CO2 EOR was used in an adjacent well, which resulted in similar additional oil recovery and hence, impurities in CO2 injection stream would not undermine efficiency of this EOR method. The results of this study, therefore, could potentially be used to substantially improve the evaluations of CO2 EOR in liquid-rich shale reservoirs.
If you are not logged in, you will receive a confirmation email that you will need to click on to start receiving the newsletter. In the shale oil business, cash flow is a life or death issue. For smaller players, money from investors and lenders is getting harder to find. Ghawar vs. Permian Basin: Is There Even a Comparison? While some try to put the two enormous oil producers toe-to-toe, the best thing to do might be to understand why they are different.
Fast-declining, older, unconventional oil wells require artificial lift experts to deal with and explore a population of miles-long horizontal wells that do not follow the established rules of thumb. After Gustavo Astie, executive manager for unconventionals at YPF, presented what he thought was an aggressive growth plan for the coming year to YPF management, he was asked: Would it be possible to go faster? A drive down a gravel road in the Loma Campana follows the steep early learning curve in the Vaca Muerta. It is easy to fixate on what it will take to extract huge volumes of oil and gas from the nearly impermeable rock within the Vaca Muerta. Añelo is a small town in an arid, sparsely populated area with a new supermarket, police station, bank, skate park, hotel, and hospital.
It will provide re ... Harkand has secured a USD 5 million contract from Swiber Offshore Mexico to perform saturation divin ... Two Bumi Armada subsidiary companies secured USD 300 million worth of contracts from ElectroGas for ... Amec Foster Wheeler has been awarded a contract by BP worth more than USD 73 million. Tam International, which provides inflatable and swellable packers for the oil and gas industry, has ... Sanchez Energy closed a deal with a subsidiary of Sanchez Production Partners to sell wellbore and a ... Penn West Petroleum has entered into a USD 321 million agreement with Freehold Royalties to sell an ... Bonterra Energy has acquired Cardium formation-focused assets in the Pembina area of Alberta, Canada ... Petrobras has sold its assets in Argentina’s Austral basin to Compañia General de Combustibles for U ... Pemex signed an agreement worth USD 1 billion with private equity firmFirst Reserve to jointly inves ... Gulfport Energy entered into an agreement to acquire Paloma Partners III for USD 300 million. Apache sold its 13% stake in the Wheatstone LNG terminal in Western Australia and 50% interest in th ... Oil and gas safety company Secorp opened a new office in Hobbs, New Mexico. Bill Barrett Corp. has signed agreements with several undisclosed recipients for the sale of the maj ... Encana said it will sell its remaining 54% stake in PrairieSky Royalty via a USD-2.4-billion Cardinal Energy entered into an agreement with an unnamed seller to acquire assets whose total daily ... Petrobras has awarded a contract, worth USD 465 million over a period of 5 years, to Aker Oilfield S ... CGG received contracts for the 3D seismic acquisition of four surveys using its marine broadband tec ... IKM Subsea, a subsidiary of IKM Group, has been awarded a contract by Eni Indonesia to provide remot ... OneSubsea, Schlumberger, and Helix Energy Solutions signed a letter of intent to develop technologie ... Premier Hytemp has committed to opening a USD-20-million, 67,000-ft2 precision engineering facility ... Expro has constructed a new 20,000‑m2 facility in Macaé, Brazil.
Last year, the SPE Board of Directors approved a new 5-year Strategic Plan, a blueprint to provide guidance on how the association can meet the needs and expectations of its members and the industry over the next several years. Late December/early January is the time of year when industry outlooks are announced, revealing company spending plans, oil price predictions, and potential stumbling blocks. The most recent report from the United Nation’s Intergovernmental Panel on Climate Change and December’s international conference on climate change held in Katowice, Poland, show that the world is not coming close to reaching the targets set in the landmark Paris Agreement of 2015. SPE is launching a new online publication and newsletter on data science and digital engineering and a new monthly newsletter on the unconventionals oil and gas sector. Slow uptake of innovation and new technology is an oft-repeated criticism of the oil and gas industry.