scholarly journals Deep seismic survey extending from Western Washington to Mist Gas Field, Oregon. Final report

1992 ◽  
Author(s):  
D.D. Hollis
2021 ◽  
Author(s):  
Mahesh S. Picha ◽  
M. Azuan B. Abu Bakar ◽  
Parimal A. Patil ◽  
Faiz A. Abu Bakar ◽  
Debasis P. Das ◽  
...  

Abstract Oil & Gas Operators are focusing on zero carbon emission to comply with government's changing rules and regulations, which play an important role in the encouragement of carbon capture initiatives. This paper aims to give insights on the world's first offshore CCS project in carbonate reservoir, where wells will be drilled to inject CO2, and store produced CO2 from contaminated fields. To safeguard the storage containment, the integrity of all wells needs to be scrutinized. Development wells in the identified depleted gas field are more than 40 years old and were not designed with consideration of high CO2 concentration in the reservoir. In consequence, the possibility of well leakage due to accelerated corrosion channeling and cracks, along the wellbore cannot be ignored and require careful evaluation. Rigorous process has been adopted in assessing the feasibility for converting existing gas producers into CO2 injectors. The required defined basis of designs for gas producer and CO2 injection wells differs in a great extent and this governs the re-usability of wells for CO2 injection or necessity to be abandoned. Three (3) new CO2 injectors with fat to slim design approach, corrosion resistant alloy (CRA) material and CO2 resistant cement are designed in view to achieve lifecycle integrity. Optimum angle of 53 deg and maintaining the injection pressure of 50 bar at 90 MSCFD rate is required for the injection of supercritical CO2 for 20 years. During well execution, challenges such as anti-collision risk, total loss scenarios while drilling in Carbonate reservoir need to be addressed before execution. The completion design is also focusing on having minimal number of completion jewelries to reduce pressure differential and potential leak paths from tubing hangar down to the end of lower completion. The selection of downhole safety valve (TRSV) type is of high importance to accommodate CO2 phase attributes at different pressure/temperature. Fiber Optic is included for monitoring the migration of CO2 plume by acquiring seismic survey and for well integrity by analyzing DAS/DTS data.


2006 ◽  
Vol 46 (1) ◽  
pp. 101 ◽  
Author(s):  
K.J. Bennett ◽  
M.R. Bussell

The newly acquired 3,590 km2 Demeter 3D high resolution seismic survey covers most of the North West Shelf Venture (NWSV) area; a prolific hydrocarbon province with ultimate recoverable reserves of greater than 30 Tcf gas and 1.5 billion bbls of oil and natural gas liquids. The exploration and development of this area has evolved in parallel with the advent of new technologies, maturing into the present phase of revitalised development and exploration based on the Demeter 3D.The NWSV is entering a period of growing gas market demand and infrastructure expansion, combined with a more diverse and mature supply portfolio of offshore fields. A sequence of satellite fields will require optimised development over the next 5–10 years, with a large number of wells to be drilled.The NWSV area is acknowledged to be a complex seismic environment that, until recently, was imaged by a patchwork of eight vintage (1981–98) 3D seismic surveys, each acquired with different parameters. With most of the clearly defined structural highs drilled, exploration success in recent years has been modest. This is due primarily to severe seismic multiple contamination masking the more subtle and deeper exploration prospects. The poor quality and low resolution of vintage seismic data has also impeded reservoir characterisation and sub-surface modelling. These sub-surface uncertainties, together with the large planned expenditure associated with forthcoming development, justified the need for the Demeter leading edge 3D seismic acquisition and processing techniques to underpin field development planning and reserves evaluations.The objective of the Demeter 3D survey was to re-image the NWSV area with a single acquisition and processing sequence to reduce multiple contamination and improve imaging of intra-reservoir architecture. Single source (133 nominal fold), shallow solid streamer acquisition combined with five stages of demultiple and detailed velocity analysis are considered key components of Demeter.The final Demeter volumes were delivered early 2005 and already some benefits of the higher resolution data have been realised, exemplified in the following:Successful drilling of development wells on the Wanaea, Lambert and Hermes oil fields and identification of further opportunities on Wanaea-Cossack and Lambert- Hermes;Dramatic improvements in seismic data quality observed at the giant Perseus gas field helping define seven development well locations;Considerably improved definition of fluvial channel architecture in the south of the Goodwyn gas field allowing for improved well placement and understanding of reservoir distribution;Identification of new exploration prospects and reevaluation of the existing prospect portfolio. Although the Demeter data set has given significant bandwidth needed for this revitalised phase of exploration and development, there remain areas that still suffer from poor seismic imaging, providing challenges for the future application of new technologies.


1983 ◽  
Vol 23 (1) ◽  
pp. 192
Author(s):  
B. L. Smith

The Merrimelia oil and gas field, 40 km north of Moomba in SA, is located on the central dome of the Gidgealpa-Merrimelia-Innamincka Trend within the Cooper/Eromanga Basins.Geophysical studies have been instrumental in the investigation of the field since the discovery of commercial Permo-Triassic gas at Merrimelia- 5 in 1970 based on the results of the Merrimelia Seismic Survey. Subsequent seismic recorded during the 1980 Karawinnie Survey resulted in the location of Merrimelia-6 which, in 1981, discovered commercial oil in the Jurassic Namur Member and Hutton Sandstone, and Triassic gas, previously unknown.To allow accurate mapping of the field's oil reserves, a detailed half kilometre grid was recorded during the 1981 Namooka Seismic Survey. The programme comprised 110 km of 24-fold Vibro- seis coverage. Interpretation of the seismic and well data has resulted in recognition of a complex stratigraphic component superimposed on the Merrimelia structural high. Considerable detailed seismic work has contributed to a better understanding of the seismic reflection sequence and hence improved geophysical prognoses.Seismic studies of the Merrimelia field are continuing as further discoveries, most recently oil in the Triassic at Merrimelia-12 and gas in the Tirrawarra Sandstone at Merrimelia-13, are made in the field area.


1983 ◽  
Vol 23 (1) ◽  
pp. 164
Author(s):  
M. David Agostini

The North Rankin gas field discovered in 1971, has been evaluated by a series of appraisal wells and refinement of this is underway through the use of a 3D seismic survey. Extensive production testing on two wells was used to establish reservoir fluid characteristics, inflow performance and to predict reservoir behaviour.The North Rankin 'A' platform has been constructed of a standard steel jacket design. Components of the structure were built in Japan, Singapore, Geraldton, Jervoise Bay and Adelaide. Provision exists for 34 wells to be drilled from the structure to exploit the southern end of the North Rankin field.Simultaneous drilling and producing activities are planned, requiring well survey and deviation control techniques that will provide a high level of confidence. Wells will be completed using 7 inch tubing, fire resistant christmas trees, and are designed to be produced at about 87 MMSCFD on a continuous basis. Process equipment on this platform is designed to handle 1200 MMSCFD and is intended primarily to dry the gas and condensate and to transfer gas and liquid to shore in a two phase 40 inch pipeline. The maintenance of offshore equipment is being planned to maximise the ratio between planned and unplanned work.The commencement of drilling activities is planned for mid 1983, with commissioning of process equipment occurring in the second quarter of 198 The North Rankin 'A' platform will initially supply the WA market at some 400 MMSCFD offshore gas rate, requiring 7 wells. The start of LNG exports is planned for April 1987. The intial gas for this will be derived from the North Rankin 'A' platform.


2017 ◽  
Vol 57 (2) ◽  
pp. 726
Author(s):  
Ronald Cupich ◽  
Birgit Cropp

2019 ◽  
Vol 131 (11-12) ◽  
pp. 2039-2055 ◽  
Author(s):  
Elana L. Leithold ◽  
Karl W. Wegmann ◽  
Delwayne R. Bohnenstiehl ◽  
Catelyn N. Joyner ◽  
Audrianna F. Pollen

Abstract Lake Crescent, a 180-m-deep, glacially carved lake located on the Olympic Peninsula in western Washington, USA, overlies the Lake Creek-Boundary Creek fault zone, a system of structures with at least 56 km of late Pleistocene to Holocene surface rupture. Investigation of the lake’s sediment, including a reflection seismic survey and analysis of piston cores, reveals evidence that the fault beneath the lake has ruptured four times in the past ∼7200 years, producing unusually thick deposits termed megaturbidites. The earthquakes triggered rockslides that entered the lake and caused displacement waves (lake tsunamis) and seiches, most recently ca. 3.1 ka. Seismic reflection results from beneath the depth of core penetration reveal at least two older post-glacial ruptures that are likely to have similarly affected the lake. The stratigraphy of Lake Crescent provides insight into the behavior of a fault system that partially accommodates regional clockwise rotation and contraction of the northern Cascadia forearc through oblique dextral shear, and highlights the potential for disruption to critical infrastructure, transportation corridors, and industry on the North Olympic Peninsula during future surface-rupturing earthquakes. Our results illustrate the potential synergism between lacustrine paleoseismology and fault-scarp trench investigations. More precise dating of strong earthquake shaking afforded by continuous accumulation of lake sediment improves earthquake histories based on trenched fault scarp exposures, which are commonly poorly dated.


2021 ◽  
Author(s):  
Haibin Di ◽  
Aria Abubakar

Abstract Robust estimation of rock properties, such as porosity and density, from geophysical data, i.e. seismic and well logs, is essential in the process of subsurface modeling and reservoir engineering workflows. Such properties are accurately measured in a well; however, due to high cost of drilling, such direct measurements are limited in amount and sparse in space within a study area. On the contrary, 3D seismic data illuminates the subsurface of the study area throughoutly by seismic wave propagation; however, the connection between seismic signals and rock properties is implicit and unknown, causing rock property estimation from seismic only to be a challenging task and of high uncertainty. An integration of 3D seismic with sparse wells is expected to eliminate such uncertainty and improve the accuracy of static reservoir property estimation. This paper investigates the application of a semi-supervised learning workflow to estimate porosity from a 3D seismic survey and 36 wells over a fluvio-deltaic Triasic gas field. The workflow is performed in various scenarios, including purely from seismic amplitude, incorporating a rough 6-layer deposition model as a constraint, and training with varying numbers of wells. Good match is observed between the machine prediction and the well logs, which verifies the capability of such semi-supervised learning in providing reliable seismic-well integration and delivering robust porosity modeling. It is concluded that the use of available additional information helps effectively constrain the learning process and thus leads to significantly improved lateral continuity and reduced artifacts in the machine learning prediction. The semi-supervised learning can be readily extended for estimating more properties and allows nearly one- click solution to obtain 3D rock property distribution in a study area where seismic and well data is available.


2003 ◽  
Vol 20 (1) ◽  
pp. 741-747 ◽  
Author(s):  
C. W. McCrone ◽  
M. Gainski ◽  
P. J. Lumsden

abstractIndefatigable is a mature dry gas field on the northeastern margin of the UK Southern North Sea Rotliegend Play fairway. The field was discovered, 49/18-1, by the Amoco operated group in 1966 and subsequent appraisal drilling established that the field extended over four blocks (i.e. 49/18, 49/19, 49/23 & 49/24). There have been several phases of development, initial production concentrated on the main horst block with first gas in 1971, followed by the west flank area in 1977/78. Then in 1987/88 the SW and SE Indefatigable satellite accumulations were brought on-stream.The Rotliegend Leman Sandstone Formation reservoir primarily consists of stacked aeolian dune sandstones (150-400 ft) of good reservoir quality (porosity 15%, permeability 100-1000 mD). However, the integration of the 1992/93 3D seismic survey, well data, reservoir pressure and production data has lead to a much more complex view of the field with 11 gas-water contacts and 15 reservoir compartments.This has resulted in an upward revision of the gas initially-in-place from 5.2 to 5.6 TCF and recoverable reserves from 4.4 to 4.7 TCF. Current work is focused on maximizing recovery from the various reservoir compartments and accessing this additional potential.


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