Preliminary absolute gravity survey results from water injection monitoring program at Prudhoe Bay

The 4D microgravity method is becoming a mature technology. A project to develop practical measurement and interpretation techniques was conducted at Prudhoe Bay, Alaska, from 1994 through 2002. Beginning in 2003 these techniques have been systematically applied to monitor a waterflood in the gas cap of the Prudhoe Bay reservoir. Approximately 300 stations in a [Formula: see text] area are reoccupied in each survey year with sub-[Formula: see text] precision absolute gravity and centimeter precision Global Positioning System (GPS) geodetic measurements. The 4D gravity measured over epochs 2005–2003, 2006–2003, and 2007–2003 has been successfully modeled to track the mass of water injected since late in 2002. A new and improved version of the A-10 field-portable absolute gravity meter was developed in conjunction with this project and has proven to be a key element in the success of the 4D methodology. The use of an absolute gravity meter in a field survey of this magnitude is unprecedented. There are substantial differences between a 4D absolute microgravity survey and a conventional gravity survey in terms of station occupation procedures, GPS techniques, and the 4D elevation correction. We estimate that the overall precision of the 4D gravity signal in each epoch is less than [Formula: see text].

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The 4D microgravity method for waterflood surveillance: Part II — Gravity measurements for the Prudhoe Bay reservoir, Alaska

Geophysics ◽

10.1190/1.2435473 ◽

2007 ◽

Vol 72 (2) ◽

pp. I33-I43 ◽

Cited By ~ 47

Author(s):

J. F. Ferguson ◽

T. Chen ◽

J. Brady ◽

C. L. Aiken ◽

J. Seibert

Keyword(s):

Water Injection ◽

Time Lapse ◽

Lessons Learned ◽

The Arctic ◽

Absolute Gravity ◽

Theoretical Investigations ◽

Gravity Measurements ◽

Series Of Experiments ◽

Prudhoe Bay ◽

Relative Gravimeter

Between 1994 and 2002, a series of experiments was conducted at Prudhoe Bay, Alaska, aimed at the development of an effective 4D (or time-lapse) gravity technique. Theoretical investigations had pointed out the potential for monitoring water injection in the [Formula: see text]-deep reservoir, but it was not clear that gravity measurements of sufficient accuracy could be made in the arctic environment. During the course of these experiments, new techniques and instrumentation were introduced and perfected for both gravity and position measurements. Gravity stations are located using high-precision global positioning system (GPS) techniques without permanent monuments. Robust methods for meter drift control have improved noise resistance in relative gravimeter surveys. Absolute gravity measurements with a field-portable instrument maintain absolute gravity levels among surveys. A 4D gravity-difference noise of [Formula: see text] standard deviation has been established at Prudhoe Bay for GPS-controlled relative gravimeter surveys. The lessons learned are now being applied to full-scale waterflood monitoring at Prudhoe Bay. The basic technique is applicable to microgravity surveys and 4D microgravity surveys for any purpose.

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THE APPLICATION OF GRAVITY INTERPRETATION TO AN INTRA CRATONIC BASIN

The APPEA Journal ◽

10.1071/aj77016 ◽

1978 ◽

Vol 18 (1) ◽

pp. 130

Author(s):

C. N. G. Dampney ◽

B. D. Johnson ◽

R. J. S. Hollingsworth

Keyword(s):

Gravity Field ◽

Measurement Accuracy ◽

Geological Structure ◽

Gravity Survey ◽

Appropriate Care ◽

Other Information ◽

Survey Results ◽

Gravity Interpretation ◽

Shallow Structure ◽

Cooper Basin

I he Cooper Basin is a good example of a tectonically complex area, and this complexity is reflected in the gravity field. The gravity field caused by the sediments is distorted by the influence of a relatively strong regional field. Nevertheless along profiles over which gravity has been measured with appropriate care, the various components of the gravity field can be analysed and separated.In the Cooper Basin the form of the regional field has been determined. As a result the structure of a major pre-Permian unconformity, which defines the base of the sediments mainly causing the gravity field anomaly, can be contoured. Other information related to some shallow structure is also derived.The pertinent point emphasized by the Cooper Basin example is that over similarly complex areas gravity survey results can only be effectively used once the various components of the field are properly analysed. Scattered regional measurements may be of some value where the regional field varies little. In general, however, a few detailed profiles must also be available to upgrade gravity interpretation to the level where it is of immediate value in the early stages of oil exploration.Specifications are therefore presented which detail gravity, elevation and positioning measurement accuracy as well as survey procedures necessary to detect geological structure at given depths.

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Gsolve, a Python computer program with a graphical user interface to transform relative gravity survey measurements to absolute gravity values and gravity anomalies

SoftwareX ◽

10.1016/j.softx.2018.04.003 ◽

2018 ◽

Vol 7 ◽

pp. 129-137 ◽

Cited By ~ 4

Author(s):

Jack McCubbine ◽

Fabio Caratori Tontini ◽

Vaughan Stagpoole ◽

Euan Smith ◽

Grant O’Brien

Keyword(s):

User Interface ◽

Computer Program ◽

Graphical User Interface ◽

Gravity Anomalies ◽

Gravity Survey ◽

Absolute Gravity ◽

Relative Gravity

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A Comprehensive Approach for Stimulating Produced Water Injection Wells at Prudhoe Bay, Alaska

10.2118/28976-ms ◽

1995 ◽

Author(s):

J.D. Fambrough ◽

R.H. Lane ◽

J.C. Braden

Keyword(s):

Produced Water ◽

Water Injection ◽

Comprehensive Approach ◽

Injection Wells ◽

Prudhoe Bay

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BEHAVIOR OF BEACH FILL AT ATLANTIC CITY, NEW JERSEY

Coastal Engineering Proceedings ◽

10.9753/icce.v14.80 ◽

1974 ◽

Vol 1 (14) ◽

pp. 80

Author(s):

Craig H. Everts ◽

Allan E. DeWall ◽

Martin T. Czerniak

Keyword(s):

New Jersey ◽

Sea Level ◽

Monitoring Program ◽

Warning System ◽

Coastal Communities ◽

Beach Sand ◽

Atlantic City ◽

Mean Sea Level ◽

Survey Results ◽

Waves And Tides

A beach monitoring program between 1962 and 1972 at Atlantic City, New Jersey was designed to observe the response of beaches to waves and tides of specific intensity and duration as a first step in developing a storm warning system for low-lying coastal communities. As a by-product of that study the behavior of beach sand following two beach replenishment projects in 1963, and again in 1970, was determined. Monitoring was done using repetitive beach surveys above mean sea level (MSL) at seven profile lines. Survey results show that following replenishment, losses of the fill material above MSL were between nine and twelve times the losses measured in adjacent non-fill areas. Loss rates were largest at the updrift end of the fill region. About two and one-half times more material appeared to move in a seasonal on-offshore direction than moved permanently alongshore and above MSL to the southwest. For each meter of beach retreat, 5 to 6 m /lineal meter of fill were lost.

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Ecological Impact of a 4-km Causeway on an Arctic Environment

Water Science & Technology ◽

10.2166/wst.1984.0070 ◽

1984 ◽

Vol 16 (3-4) ◽

pp. 387-397

Author(s):

J M Colonell ◽

G A Robilliard

Keyword(s):

Environmental Impact ◽

Ecological Impact ◽

Monitoring Program ◽

Beaufort Sea ◽

Regulatory Agencies ◽

Arctic Environment ◽

The Impact ◽

Prudhoe Bay

The Prudhoe Bay Causeway is a gravel-fill structure that extends 4 km into the Beaufort Sea at Prudhoe Bay, Alaska. Concern over the impact of this structure on the marine Arctic environment prompted regulatory agencies to require owners of the causeway to sponsor a multidisciplinary monitoring program that encompasses the physical and biological realms of possible impact. This paper describes how such concerns are being addressed and also includes results of the initial studies of possible environmental impact of the causeway.

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