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A Monte Carlo model is, in principle, just a worksheet in which some cells contain probability distributions rather than values. Thus, one can build a Monte Carlo model by converting a deterministic worksheet with the help of commercial add-in software. Practitioners, however, soon find that some of their deterministic models were constructed in a way that makes this transition difficult. Redundancy, hidden formulas, and contorted logic are common features of deterministic models that encumber the resulting Monte Carlo model. Likewise, presentation of results from probabilistic analysis might seem no different from any other engineering presentation (problem statement, summary and conclusions, key results, method, and details).
In contrast to monopole logging tools, dipole acoustic devices can excite a low-frequency flexural wave in the borehole at shear velocity. Low-frequency ( 1 kHz) dipole sources allow for shear-velocity determination that is much closer to seismic shear waves and permits acquisition of direct-shear velocities in slow and fast formations. However, increased noise (i.e., a lower signal-to-noise ratio) is one limitation of low-frequency operation. Noise has been reduced through improved acquisition electronics, the use of semi-rigid tool designs, and by choosing the operational mode of the dipole source. A semi-rigid tool body not only reduces the influence of the tool body on the measurement but also permits operation in deviated wells.
Figure 1G.2 – Vectorial illustration of the use of three-axis magnetometer and accelerometer data to calculate the inclination and azimuth of the directional-survey tool and of the wellbore itself. Vertical scale on the Well Path Plot is true vertical depth (TVD). Depth markers on the Plan View trace are measured depths. The Tabular Listing links the two depth scales at measurement stations and contains the wellbore deviation, azimuth, and coordinates at the points of measurement. Figure 1G.5 – Principles of the minimum curvature method for modeling the well path between directional survey stations A and B, drawn in the plane of the wellbore.
At SPE forums, oil and gas professionals come together from across the globe to discuss the future of technical innovations and advancements, and to network with one another. SPE values the participation of all persons at its events, and seeks to provide them with a respectful, harassment-free and inclusive environment for all, regardless of race, color, religion, sex, national origin, disability status, ancestry, citizenship status, age, gender, sexual orientation, and others. Therefore, SPE has adopted this virtual Forum Code of Conduct ("Code of Conduct"): Adhere to the SPE Forum Guidelines Participants are expected to attend every session. Slides are limited, allowing maximum time for informal discussions and exchange of experience. Forums are conducted off the record to support the free interchange of information and ideas.
As SPE's Distinguished Lecture series wraps up its SPE section presentations for 2020–2021, a new series of virtual presentations stretches through the summer, providing access for all SPE members. Three of the live virtual presenters will be speaking on topics in the health, safety, environment, and sustainability (HSES) discipline. Each year, SPE selects industry experts, nominated by their peers, to share their knowledge and expertise at SPE section meetings. Despite the many challenges faced this season, SPE's Distinguished Lecturers gave more than 450 virtual presentations to members in more than 191 SPE sections countries around the world. Starting on 22 June, 22 presentations will be made available live virtually, broadening the audience from SPE section meetings to all of SPE's membership.
A blowout in Ohio in 2018 was the first ever where the emissions could be measured from space, though it was at best a rough estimate based on data gathered on the 13th day after the XTO Energy well control event began. A year later, a blowout of a Devon well near Victoria, Texas, was measured starting the day after it occurred, with data collected on 3 days over the next 2 weeks. Using the measurement of carbon dioxide, it was estimated that the flare was 87% effective in burning about 4,800 metric tons of the leaking methane gas. Emission estimates varied wildly, and both the Ohio and Texas efforts to use satellites led to technical papers to consider how they addressed this challenge. For those with blowouts next year, chances are a lot better methane-emission data would be available because of the launch of a constellation of specialized methane-measurement satellites by the two groups that played a key role in the earlier tests. In presentations this week at CERAWeek by IHS Markit, GHGSat said it has two methane-detection satellites in orbit and plans the launch of eight more, and the Environmental Defense Fund (EDF) said it is moving forward with the launch of its first one next year.
Acoustic logs provide the primary means for evaluating the mechanical integrity and quality of the cement bond. Acoustic logs do not measure cement quality directly, rather, this value is inferred from the degree of acoustic coupling of the cement to the casing and to the formation. Properly run and interpreted, cement-bond logs (CBL) provide highly reliable estimates of well integrity and zone isolation. Just as filtrate invasion and formation alteration may produce changes in formation acoustic properties, and thus variation in acoustic logs over time, so too, cement-bond logs may vary over time as the cement cures and its properties change. Modern acoustic cement-evaluation (bond) devices are comprised of monopole (axisymmetric) transmitters (one or more) and receivers (two or more). They operate on the principle that acoustic amplitude is rapidly attenuated in good cement bond but not in partial bond or free pipe. Conventional CBL tools provide omnidirectional measurements, while the newer radial cement-evaluation tools provide azimuthally sensitive measurements for channel evaluation. Tool response depends on the acoustic impedance of the cement, which, in turn is function of density and velocity.
Preventing such failures is critical to maintaining well production. Echo amplitude and travel time provide images of the condition of the inside casing surface (e.g., buildup, defects, and roughness such as pitting and gouges) (Figure 1), and travel-time and resonant-frequency analysis provide casing thickness (Figure 1). Holes in the casing are visible in the series of ultrasonic images that are based on amplitude (left) and corrected travel time (right). The center 3D images show the pipe in 90 quadrants. The image shading is generated from the amplitude data (courtesy of SPE). In this example, casing radius and shape are presented as log curves and image maps and deformed casing is easily identified (courtesy of Baker Atlas).
Oil industry executives surveyed last year ranked the potential positive impact of big data analytics at the top of the list of trends, higher than even changes in oil demand. That bold conclusion was from a survey by accounting firm Ernst and Young (EY), putting big data analytics among the top trends that could aid business growth in the next 3 years, even above the demand swings that move oil prices. The survey may have reflected the mood last summer when the outlook for oil consumption looked so weak that cost saving was the only path to better results. "The survey speaks to a high-level ambition across the operator community to use digital as a mechanism to drive down costs," said Toby Summers executive director for EY. The promise there is that digital can allow them to scale up operations with fewer hires in good times and scale back with fewer layoffs when the cycle turns down. These projects also cost less than other cost-cutting options.
A good nomination is key to communicating the qualifications of a candidate to the award committee. SPE recognizes the diverse cultures represented in the membership. Following best practices gives all members an equal opportunity for to participate successfully in the SPE International Awards Program. Candidates must be nominated by a colleague. The nominator must take the action to ensure the quality of the nomination.