TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe mechanism of wetting phase flow into and across fractures was determined for stacked core plugs using highly water-wet and less water-wet chalk and several fracture widths and flow rates. Magnetic resonance imaging (MRI) was used to measure 2D saturation distributions in the matrix along the flow axis and 2D spatial distributions of the wetting and nonwetting phases in the fracture.For the strongly water-wet system, even at high flow rates, the inlet plug reached its spontaneous imbibition endpoint water saturation before the water entered the fracture. When water entered the fracture, gravity segregation resulted in the displacement of oil from the bottom of the fracture and upward. The rate of displacement was determined by the water injection rate. At less-water-wet conditions, the water produced a dispersed front that allowed water; at both high and low flow rates, to flow across the fracture and into the outlet plug as if there was no fracture. MRI images showed that water droplets formed on the outlet face of the inlet plug, formed bridges across the fracture and provided a path for water movement into the outlet plug while the oil phase was still being produced from the inlet plug. With time the bridges grew in size, coalesced and dropped to the bottom of the fracture eventually filling the fracture with water. At wider fracture widths the coalescence occurred earlier and the fracture was filled sooner. The capillary continuity provided by the bridges suggested a viscous component contributing to the total oil recovery in the fractured system for less than highly water-wet conditions.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractAt three different wettabilities, two stacked outcrop core plugs, separated by a 1 mm fracture, were waterflooded. During the experiment in-situ fluid saturations were monitored with Magnetic Resonance Imaging (MRI). The sequence of 2D MRI images corroborated earlier lower resolution, larger scale experimental results on the effect of fractures during waterflooding at various wettabilities. The MRI images of oil saturation development in the fracture clearly revealed two distinct transport mechanisms for the wetting phase, water, across the fracture at several wettability conditions. When strongly-water-wet, the first core reached its spontaneous imbibition endpoint before water left the matrix and entered the fracture. The displaced water flowed down the exit face to the bottom of the fracture and displaced the oil upward at the rate of water injection. At less-water-wet conditions water droplets formed on the exit face of the first plug and grew large enough to form individual bridges between the two plugs. This happened well before the first plug reached its spontaneous imbibition endpoint. Under these conditions, the fracture filled slowly, as the bridges increased in diameter and additional bridges formed. Due to the capillary continuity of the wetting phase, a viscous pressure drop was established across the stacked core plugs, providing a viscous component to the total oil recovery.

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This paper we present what is fatigue ?and what is fracture? we will discuse on design aspects related to fatigue failure, an important mode of failure in engineering components. Fatigue failure results mainly due to variable loading or more precisely due to cyclic variations in the applied loading . A fatigue failure begins with a small crack; the initial crack may be so minute and can not be detected. The crack usually develops at a point of localized stress concentration like discontinuity in the material, such as a change in cross section, a keyway or a hole.for design pavement flexible or regid pavement cycle life or how many percentage of material damaged.one parameter of design in all branch of engineering is standard of test of fatigue and fracture.for example in pavement number of axles ,number of tires ,thickness of pavement ,kind of Load is effect on fatigue and fracture.

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