Question

GEOE 357 Subsurface Methods-Lab 9b Using and interpreting Allan Sections-30 Points This assignment is due next lab Allan Sections are important tools in evaluating fault-bounded reservoirs. As said in 1996: Allan Sections should be created for all prospects where a fault forms one of the boundaries of the trap. In cases where a sand is isolated in a thick shale section, it may be sufficient to check that the vertical separation exceeds the true vertical thickness of the sand at all points along the fault. In cases where several sands are potential objectives in an alternating sand-shale sequence, detailed Allan Sections" need to be created from the maps, either by hand or using computer programs such as FAPS. Where "Allan Sections" indicate the potential for sand-on-sand juxtaposition, the sealing potential of faults should be estimated using either Clay Smear Potential or Shale Gouge Ratio. Estimating either of these factors is easie st using computer programs such as FAPS (Fault Analysis Projection System, ftware written by Badley Earth Sciences, Ltd.)" - James C. Brenneke, Subsurface Consultants & Associates, formally Royal Dutch Shell. Procedure to interpret oil-water contacts in five sands on either side of a scissoring normal It. Attached are copies of the hanging wall and footwall representations of the 5 sands, and a d structure contour map. The figures are derived from "Case 2" in Allan (1989). The figures are similar, but not identical to, Figures 2, 3 and 4 in the article by Allan (1989) Assume the footwall is stable and that the hangingwall has moved down and rotated. The hangingwall section has moved down by 400 ft on the left side of the section and down by 50 ft on the right. You will want to neatly trace the hangingwall contacts onto the footwall sheet (so horizontal will be parallel to the bounding box). Assume full charge of oil (no gas) from downdip locations into both the footwall and hangingwall. Look for the juxtapositions across the fault, assume oil will leak across the fault where reservoirs are in contact, interpret migration directions and spill points, and draw oil water contacts on the Allan Sections. . Assume the structure map is on the fop sandstone. Interpret the approximate positions of oil- water contacts in the top sandstone on the structure map See the article by Allan for clarification. . TURN IN-The footwall section, with the hangingwall sands traced onto it, and the structure contour map with arrows showing spill points from reservoirs into "thief" sands. Show approximate oil-water contacts for top sand on the structure map. Grading will be based on: Followed directions-work is complete. Rationality of oil-water contacts Neatness

Answer 1

A pressure system is a relative peak or lull in the sea level pressure distribution. The surface pressure at sea level varies minimally, with the lowest value measured 87 kilopascals (26 inHg) and the highest recorded 108.57 kilopascals (32.06 inHg). High- and low-pressure systems evolve due to interactions of temperature differentials in the atmosphere, temperature differences between the atmosphere and water within oceans and lakes, the influence of upper-level disturbances,^[jargon] as well as the amount of solar heating or radiationized cooling an area receives. Pressure systems cause weather to be experienced locally. Low-pressure systems are associated with clouds and precipitationthat minimize temperature changes throughout the day, whereas high-pressure systems normally associate with dry weather and mostly clear skies with larger diurnal temperature changes due to greater radiation at night and greater sunshine during the day. Pressure systems are analyzed by those in the field of meteorology within surface weather maps.