PROBABILITY STUDIES IN THREE VARIANTS: SEISMIC VELOCITY, DEPTH, AND LITHOLOGY

Geophysics ◽  
1963 ◽  
Vol 28 (1) ◽  
pp. 46-86 ◽  
Author(s):  
Ethel Ward McLemore
Keyword(s):  
Statistical Inference ◽  
Seismic Velocity ◽  
San Joaquin Valley ◽  
Oil Fields ◽  
Velocity Information ◽  
Rio Bravo

In an effort to determine if lithology—shales, sands, or a mixture of both—can be inferred from interval seismic velocity values, probability theories of statistical inference were applied to data from 16 wells shot for velocity information and from electric logs of the wells in the San Joaquin Valley, California, area. Average velocities, velocity functions, and probability ratios were derived for the three classes of lithology, for all data, for the two general areas, and for three individual oil fields: Wasco, Rio Bravo, and Coalinga.

GROUNDWATER QUALITY IN AQUIFERS NEAR AND OVERLYING THE ELK HILLS AND NORTH COLES LEVEE OIL FIELDS, SAN JOAQUIN VALLEY, CALIFORNIA

2020 ◽  
Author(s):  
John Warden ◽  
◽  
Matthew K. Landon ◽  
Peter B. McMahon ◽  
Janice M. Gillespie ◽  
...  
Keyword(s):  
Groundwater Quality ◽  
San Joaquin Valley ◽  
Oil Fields

SEISMIC VELOCITIES IN THE SOUTHEASTERN SAN JOAQUIN VALLEY OF CALIFORNIA

Geophysics ◽  
1941 ◽  
Vol 6 (4) ◽  
pp. 327-355
Author(s):  
E. J. Stulken
Keyword(s):  
Seismic Data ◽  
Seismic Velocity ◽  
San Joaquin Valley ◽  
Seismic Velocities ◽  
Velocity Measurements ◽  
Constant Depth ◽  
Entire Area ◽  
Velocity Gradients ◽  
Velocity Changes ◽  
First Time

For the first time, seismic velocity measurements from well surveys have been made intensively enough to justify an analysis of the velocity field in an entire area instead of just along lines between wells. Maps are drawn showing velocity changes in the southeastern San Joaquin Valley of California. A portion of the valley floor in the neighborhood of Bakersfield, about twenty‐five miles wide and thirty‐five miles long, was chosen for study because of the number of wells in the area whose velocities were known. Differences in average velocity of 1700 feet per second for a constant depth are observed, and horizontal velocity gradients averaging over 100 feet per second per mile are computed. Correction schemes for the adjustment of seismic data are suggested, and correction maps shown. An attempt is made to establish a connection between stratigraphy and seismic velocity. Comparative study of the logs of wells and the velocities observed in them yields certain qualitative conclusions, but attempts to express the relation in a quantitative way fail.

THE DEVELOPMENT OF A NEW METHOD OF SEISMIC VELOCITY DETERMINATION

Geophysics ◽  
1952 ◽  
Vol 17 (3) ◽  
pp. 560-574 ◽  
Author(s):  
F. P. Kokesh
Keyword(s):  
Conventional Method ◽  
Explosive Charge ◽  
Velocity Measurement ◽  
Seismic Velocity ◽  
Seismic Energy ◽  
New Method ◽  
Seismic Velocities ◽  
The Past ◽  
Velocity Information ◽  
Made In

The conventional method of making velocity surveys in bore holes is inherently expensive, time consuming, and inconvenient, and has a tendency towards non‐uniformity of results. With increasing recognition of the importance of seismic velocity information in the evaluation of seismograph data, the attention of geophysicists is turning towards means of overcoming the obstacles standing in the way of obtaining velocity information in greater volume. Considerable interest has recently been aroused in a new method of measuring seismic velocities wherein the explosive charge is placed in the hole and the seismic energy is picked up with multiple detector groups placed on the surface. Experimentation carried on during the past year indicates that the new method is quite workable. Casing perforator guns of the conventional bullet type have given results to depths exceeding 8,000 ft. with complete safety. Some experimentation with primacord as the explosive has given encouragement as a means of increasing the depth at which the method may be used. Substantial improvements have been made in the manner of obtaining the time break. This paper attempts to outline the basic problems of velocities and their measurement and describes the preliminary development that has been done thus far on the new method of velocity measurement.

scholarly journals Occurrence and Sources of Radium in Groundwater Associated with Oil Fields in the Southern San Joaquin Valley, California

2019 ◽  
Vol 53 (16) ◽  
pp. 9398-9406 ◽  
Author(s):  
Peter B. McMahon ◽  
Avner Vengosh ◽  
Tracy A. Davis ◽  
Matthew K. Landon ◽  
Rebecca L. Tyne ◽  
...  
Keyword(s):  
San Joaquin Valley ◽  
Oil Fields

THE MUTINEER COMPLEX AND EXETER OIL DISCOVERIES: MUTINY IN THE DAMPIER

2003 ◽  
Vol 43 (1) ◽  
pp. 273
Author(s):  
K.A. Auld ◽  
J.E.P. Redfearn
Keyword(s):  
Velocity Gradient ◽  
Seismic Velocity ◽  
Oil Fields ◽  
3D Seismic ◽  
Time Data ◽  
Southern Limit ◽  
Integration Of Technology ◽  
Critical Components ◽  
Structural Closure ◽  
Commercial Oil

The oil discoveries at Norfolk–1 and Exeter–1 in the Northern Dampier Sub-basin (permit WA-191-P) have realised major commercial potential in an area with a prolonged exploration history. This paper presents the results of the drilling campaign which was undertaken in 2002 comprising two successful exploration discovery and five appraisal wells. The Norfolk–1 (28 m gross oil column), Norfolk–2 (9 m oil column), Exeter–1 (23 m oil column), Mutineer–3 (8 m oil column) and finally Exeter–2 (12 m oil column) confirmed a significant commercial oil volume within the Jurassic Angel Sandstones.The recent exploration of this area has improved understanding of the geology through the integration of technology with geoscientific understanding. Highs have been revealed from seismic time data using advanced 3D seismic techniques and sophisticated depth conversion processes.The time structural high of the Mutineer area was first tested by Bounty–1 in 1983 which is now mapped outside the southern limit of closure. Pitcairn–1 was drilled in 1997 discovering three thin oil columns and was followed by a near crestal well at Mutineer–1B drilled 2.6 km northwest of Pitcairn–1 in 1998, discovering an 8m column. The key issue was the understanding of the velocity gradient and depth conversion over the Mutineer Complex which revealed the true structural picture.This paper summarises results of the exploration and appraisal wells drilled and describes the evolution of the structural/stratigraphic understanding of the area, covering critical components hindering the oil field’s early detection. The first component is a significant seismic velocity gradient which causes true structural closure to be significantly offset from the time closure. The second component is the reservoir pressures within the oil reservoir and older sandstone intervals within the Angel and Legendre Sandstones show differences due to hydrodynamic cells and/or depletion resulting from production from the adjacent NWS Venture oil fields. The final component is the oil is primarily reservoired in the top Angel Sandstone, belonging to the J40 sequence and is sealed by a thin shale from the underlying mainly water bearing sandstones (J35/J30 and Legendre Sandstones).The combined reserves for the Mutineer Complex and Exeter Oil Fields reservoired in these laterally continuous turbidites are estimated to be 70–160 MMBBL recoverable.

Optimum seismic velocity estimators

Geophysics ◽  
1984 ◽  
Vol 49 (11) ◽  
pp. 1861-1868 ◽  
Author(s):  
R. L. Kirlin ◽  
Lois A. Dewey ◽  
Jonathan N. Bradley
Keyword(s):  
Seismic Velocity ◽  
A Priori ◽  
Mean Square ◽  
Least Mean Square ◽  
A Priori Information ◽  
Likelihood Estimator ◽  
Velocity Variance ◽  
Velocity Information ◽  
Priori Information ◽  
Test Use

Six “optimum” estimators for the root‐mean‐square (rms) seismic velocity are given and analyzed by simulation for rms error. Two of the estimators are used to test use of a priori velocity information in a Kalman‐type improvement on the time measurements. Parameters varied include center‐point depth (time), a priori velocity variance, and interdelay‐estimate correlation. The maximum likelihood estimator is shown to be best when a priori information is relatively good, but a least‐mean‐square estimator is equally good otherwise.

Basin architecture and density structure beneath the Strait of Georgia, British Columbia

2003 ◽  
Vol 40 (7) ◽  
pp. 965-981 ◽  
Author(s):  
C Lowe ◽  
S A Dehler ◽  
B C Zelt
Keyword(s):  
Seismic Velocity ◽  
Gravity Data ◽  
Velocity Model ◽  
Seismic Structure ◽  
Strait Of Georgia ◽  
3 Dimensional ◽  
The North ◽  
Georgia Basin ◽  
Geologic Interpretation ◽  
Velocity Information

Georgia Basin is located within one of the most seismically active and populated areas on Canada's west coast. Over the last decade, geological investigations have resolved important details concerning the basin's shallow structure and composition. Yet, until recently, relatively little was known about deeper portions of the basin. In this study, new seismic velocity information is employed to develop a 3-dimensional density model of the basin. Comparison of the calculated gravity response of this model with the observed gravity field validates the velocity model at large scales. At smaller scales, several differences between model and observed gravity fields are recognized. Analysis of these differences and correlation with independent geoscience data provide new insights into the structure and composition of the basin-fill and underlying basement. Specifically, four regions with thick accumulations of unconsolidated Pleistocene and younger sediments, which were not resolved in the velocity model, are identified. Their delineation is particularly important for studies of seismic ground-motion amplification and offshore aggregate assessment. An inconsistency between the published geology and the seismic structure beneath Texada and Lasqueti Islands in the central Strait of Georgia is investigated; however, the available gravity data cannot preferentially validate either the geologic interpretation or the seismic model in this region. We interpret a northwest-trending and relatively linear gradient extending from Savory Island in the north to Boundary Bay in the south as the eastern margin of Wrangellia beneath the basin. Finally, we compare Georgia Basin with the Everett and Seattle basins in the southern Cascadia fore arc. This comparison indicates that while a single mechanism may be controlling present-day basin tectonics and deformation within the fore arc this was not the case for most of the Mesozoic and Tertiary time periods.

Using San Joaquin Valley Oil Fields as a Technology Test Bed To Mature Steamflood Technology

2012 ◽  
Author(s):  
John K. Stevenson ◽  
Ronald A. Behrens ◽  
Stephen David Cassidy
Keyword(s):  
San Joaquin Valley ◽  
Oil Fields ◽  
Test Bed
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