Abstract The Scott Field, located in the UK Central North Sea, is in a mature stage of development. The Scott platform has been on production since 1993, when the Scott Field came on stream, followed in 1993 by the subsea tie-back of the Telford Field development, located to the south of Scott. By 2005 the Scott Field had produced 400×10 6 boe cumulative production. However, the field was producing at water cuts approaching 90% and the previously completed 2002–2004 infill drilling campaign had not met expectations. A change in strategy was undertaken in the subsequent 2005–2007 Scott drilling campaign, which yielded positive results, adding reserves and significantly increasing platform export rates. The focus moved from peripheral targets towards the edge of the field to lower risk targets closer to existing well control. Success was also attributed to focusing on the seismic interpretation of block bounding faults in poorly imaged areas of the field, allowing identification of small fault-bound targets. The recent drilling has demonstrated that significant value can be found in small and often complex accumulations within an extensively drilled mature field.

ABSTRACT In late Wisconsin time, the Purcell Trench lobe of the Cordilleran ice sheet dammed the Clark Fork of the Columbia River in western Montana, creating glacial Lake Missoula. During part of this epoch, the Okanogan lobe also dammed the Columbia River downstream, creating glacial Lake Columbia in northeast Washington. Repeated failure of the Purcell Trench ice dam released glacial Lake Missoula, causing dozens of catastrophic floods in eastern Washington that can be distinguished by the geologic record they left behind. These floods removed tens of meters of pale loess from dark basalt substrate, forming scars along flowpaths visible from space. Different positions of the Okanogan lobe are required for modeled Missoula floods to inundate the diverse channels that show field evidence for flooding, as shown by accurate dam-break flood modeling using a roughly 185 m digital terrain model of existing topography (with control points dynamically varied using automatic mesh refinement). The maximum extent of the Okanogan lobe, which blocked inundation of the upper Grand Coulee and the Columbia River valley, is required to flood all channels in the Telford scablands and to produce highest flood stages in Pasco Basin. Alternatively, the Columbia River valley must have been open and the upper Grand Coulee blocked to nearly match evidence for high water on Pangborn bar near Wenatchee, Washington, and to flood Quincy Basin from the west. Finally, if the Columbia River valley and upper Grand Coulee were both open, Quincy Basin would have flooded from the northeast. In all these scenarios, the discrepancy between modeled flood stages and field evidence for maximum flood stages increases in all channels downstream, from Spokane to Umatilla Basin. The pattern of discrepancies indicates that bulking of floods by loess increased flow volume across the scablands, but this alone does not explain low ­modeled flow stages along the Columbia River valley near Wenatchee. This latter discrepancy between modeled flood stages and field data requires either additional bulking of flow by sediment along the Columbia reach downstream of glacial Lake Columbia, or coincident dam failures of glacial Lake Columbia and glacial Lake Missoula.

Abstract When we think of geophysical interpretation, seismic interpretation often comes to mind immediately. However, many other geophysical methods are used in geophysical interpretation, and we briefly consider two of them here — the gravity and magnetics methods. These are often termed potential-field methods because they deal with force fields derivable from potential energy functions. Potential fields have been used in prospecting for minerals in the mining industry and as reconnaissance tools in the petroleum industry. Nettleton (1971 , p. ix) terms the use of gravity and magnetics methods as “the other five percent,” because the seismic method accounts for 95% of expenditures in geophysical exploration for petroleum. However, this does not mean that potential-field methods make an inconsequential contribution. Although these methods have less resolving power than seismic prospecting methods, they are generally less expensive. As a rule of thumb, Nettleton gives comparative costs of magnetic, gravity, and seismic data as 1:10:100. Gravity exploration is sensitive to the anomalous mass of a subsurface body, whereas magnetic surveys are sensitive to magnetic susceptibility of rock bodies. Gravity exploration uses gravimeters, and magnetic surveys use magnetometers. Good descriptions of these instruments are given in Telford et al. (1976) . Gravimeters and magnetometers can obtain measurements in the air, on sea, on land, and inside the borehole. Potential-field methods are useful in many aspects of exploring for petroleum traps, including analysis of source-rock deposition, source maturation, hydrocarbon migration, seals, and timing of emplacement of each component of the petroleum system. These

Abstract Conventional seismic refraction methods aim to determine the spatial distribution of seismic wave velocities in the subsurface. Seismic wave velocities can be related to such geologic and petrophysical parameters as rock type, porosity, weathering, jointing, water saturation, and elasticity. Seismic refraction methods have been applied to petroleum exploration, the search for groundwater, the investigation of engineering sites, the exploration of alluvial deposits, and the correction of weathering effects for seismic reflection surveys. Descriptions of instrumentation and field operations, as well as the fundamental principles based on raypath theory, can be found in Dobrin (1976) and Telford et al (1976). An introduction to the theoretical development using the wave equation was presented in Grant and West (1965). There are numerous interpretation methods, ranging from the very simple in basic assumptions and ease of use to the complex. Dobrin (1976) gives an excellent summary of most of the published methods, and, together with the outstanding volume on seismic refraction prospecting edited by Musgrave( 1967), provides an ideal starting point for those who seek familiarity with one of the most challenging fields of geophysics. The aim of this monograph is to propose a new interpretation method, the generalized reciprocal method (GRM), which has many advantages compared with the previously published methods. The GRM can define layers with varying thicknesses and seismic velocities, unlike the conventional intercept time method (Ewing et al, 1939; Dooley, 1952; Adachi, 1954; Mota, 1954), or the critical distance method (Heiland, 1963, p. 527). However, a redefinition of the intercept time in chapter 9