Lesson No. 42: Linear Distribution of Velocity—VI. Well Shooting Theory and Practice
Published:January 01, 1959
As was mentioned on page 223, the “shooting” of a well, by which we mean a survey of the variation of seismic velocity with depth using the travel-times of seismic waves from the surface to a pickup at points down a bore hole, is an excellent means of determining whether our hypothesis of linear variation of velocity with depth may be used in the area. At the same time we determine what values of 'lio and a are most suitable for that area.
Consider (Figure 110) a well into which a pickup is lowered. We shall consider the well-head W as being at a distance d from a shot-point o. The pickup P is at a variable depth h in the well. Assuming the linear distribution of velocity, v= vo+ah, the travel-time of a seismic wave from 0 to the pickup P is then obtained by the relation (17) on page 237; namely,
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Lessons in Seismic Computing
“An elementary text and problem book containing 44 lessons in seismology arranged for selection or combination to cover the normal 36-week course, or for condensation into an 18-week course. The lessons begin without assuming more than secondary school mathematics. An elementary knowledge of calculus is desirable, though not required, for the last half of the book.”