0 SECURE LUBRICATION
Liquid f m thecasing flaws between
the rear casing and the magnet lining
w h i i prevents clogging. The fluid is
then forced to fkw to the rear bushing
then through the shaft to the front
bushing. This flow guarantees perfect
lubricat
Geophysical Data Processing 19
Frequency domain
Time domain
(a)
(b)
Sinc
function
fc
f
(c)
t
(d)
Filter
operator
Fig. 2.16 Design of a digital lowpass
lter.
(BR) in terms of their frequency response. Frequency
lters are employed when the signal and noise
Magnetic field (nT)
Geophysical Data Processing 9
600
(a)
200
500
400
300
0
10
20
30
40
50
Distance (m)
(a)
Ground velocity
(106 m/s)
Fig. 2.1 (a) A graph showing a typical
magnetic eld strength variation which
may be measured along a prole. (b) A
graph
18 Chapter 2
Waveform
Signal function
Crosscorrelation
function
S2
S1
S3
Fig. 2.14 Crosscorrelation to detect
occurrences of a known signal concealed
in noise. (After Sheriff 1973.)
Signal positions
in waveform
(a)
(b)
xx()
random, and usually due to ef
Geophysical Data Processing 15
(a)
(b)
(c)
(d)
(e)
(f)
Fig. 2.11 Examples of ltering. (a) A spike input. (b) Filtered output equivalent to impulse response of lter. (c) An input comprising two
spikes. (d) Filtered output given by summation of two impulse
Geophysical Data Processing 17
Waveform 1
Waveform 2
lag
Crosscorrelation function
Fig. 2.13 Crosscorrelation of two
identical waveforms.
ve lag
centred on the time value at which the signal function
and its concealed equivalent in the waveform are in
Amplitude density
12 Chapter 2
Phase
Frequency
Frequency
Fig. 2.7 Digital representation of the continuous amplitude and
phase spectra associated with a transient waveform.
thin frequency slices, with each slice having a frequency
equal to the mean freque
14 Chapter 2
Amplitude
Input
Input
displacement
Output
W
Output
displacement
Time
Fig. 2.9 The principle of ltering illustrated by the perturbation
of a suspended weight system.
input spikes and scaled according to the individual spike
amplitudes. Since a
Geophysical Data Processing 13
Time domain
Frequency domain
(a)
(b)
(c)
(d)
Fig. 2.8 Fourier transform pairs for
various waveforms. (a) A spike function.
(b) A DC bias. (c) and (d) Transient
waveforms approximating seismic pulses.
Time
Frequency
t=0
In th
2
Geophysical data processing
2.1 Introduction
Geophysical surveys measure the variation of some
physical quantity, with respect either to position or to
time. The quantity may, for example, be the strength of
the Earths magnetic eld along a prole across
10 Chapter 2
signicant loss of information content as long as the frequency of sampling is much higher than the highest
frequency component in the sampled function. Mathematically, it can be proved that, if the waveform is a sine
curve, this can always be
Geophysical Data Processing 11
T
(a)
8
8
(a)
(b)
(b)
Fig. 2.4 (a) Periodic and (b) transient waveforms.
Fig. 2.5 Complex waveforms resulting from the summation of
two sine wave components of frequency f and 2f. (a) The two sine
wave components are of equa
Specialized bottomhole assemblies
In developed fields, where drilling tendencies and formation characteristics are
well known, it is often possible to build or drophole angle with a reasonable
degree of control by using drill collars, stabilizers, reamers
Cuttings Transport
As hole inclination angle deviates beyond about 10 from vertical, the inclined,
generally eccentric annulus begins to pose cuttings transport problems that are
not encountered in vertical wells. For example, as hole angle approaches the
Well Trajectory Planning
Careful planning, always an important factor in minimizing well costs, is especially
critical in directional drilling. The starting point
in planning a directional well is to establish the target coordinates with respect to
the su
Survey Tools
Mechanical Drift Indicator
The oldest and simplest type of directional survey tool is the mechanical drift
indicator ( Figure 1 ).
Figure 1
This device works on a pendulum, or plumbob principle. It gives no indication of
azimuth, but measure
Drill String Considerations
As inclination angle increases in a directional or horizontal well, the borehole walls
support more of the drill string weight. This contact, along with the capstan effect
(i.e., the normal force caused by the deformation of an
16 Chapter 2
2.4.2 Deconvolution
Deconvolution or inverse ltering (Kanasewich 1981) is a
process that counteracts a previous convolution (or
ltering) action. Consider the convolution operation
given in equation (2.5)
y(t) = g (t) * f (t )
y(t) is the lter
20 Chapter 2
forms themselves are presented in a form in which they
simulate an image of the subsurface structure. The
most obvious examples of this are in seismic reection
(Chapter 4) and groundpenetrating radar (Chapter 9)
sections, where the waveform
'Fable 222
Friction losses in pipes carrying water
Among the many empirical formulae for friction losses that have
been proposed that of Williams and IIaaen has been most widely
used. In a convenient form it reads:
in which
f = friction head tn ft of liq
Pumping of Liquids
Table 31
General Types or Classification of Pumps
All types will not be treated in detail, but consideration of
their particular features is important in many situations.
Centrifugal
Rotary
Reciprocating
1. Centrifugal
2. Propeller
3.
luid Flow
159
Simpson, L. L. and Weirick, M. L.,
Designing Plant Piping,
Chem. Eng. Deskbook, April 3, 1978, p. 35.
Yu, F. C., How to Calculate Optimum Pipe Size for Liquids,
Hydrocarbon Processing, vol. 72, no. 6, June 1993, p. 67.
Soliman, R. M. and Col
158
Applied Process Design for Chemical and Petrochemical Plants
Quandt, E., Analysis of GasLiquid Flow Patterns, A.I.Ch.E., 6th
Natl Heat Transfer Conference, Boston, Mass., Aug. 1963.
Wohl, M. H., Rheology of NonNewtonian Materials, Chem.
Eng., vol. 7
Chapter
Pumping of Liquids
5. determine the important avaiZab2e net positive suction head (NPSHJ for the pump suction side
Pumping of liquids is almost universal in chemical and
petrochemical processes. The many different materials
being processed require
Fluid Flow
t = Latent heat of evaporation of steam at flash pres,
sure, Btu/lb
1 = Horizontal distance from opening to point where
flow stream has fallen one foot, in.
M = MU, = molecular weight
MR
=
Universal ga,s constant
n
=
Number o f vertical rises (
Applied Process Design for Chemical and Petrochemical Plants
154
Nomenclature
A = Internal crosssection area for flow, sq ft; or area of
orifice, nozzle, or pipe, sq ft.
F = Factor in Babcocks steam flow equation
FD = Friction pressure loss (total) at de
Applied Process Design for Chemical and Petrochemical Plants
156
Greek Symbols
p = Ratio of internal diameter of smaller to large pipe
sizes, or for orifices or nozzles, contractions or
enlargements
y = Kinematic viscosity, sq ft/sec
y = Surface tension o
Table 222: Cameron Hydraulic Data (cont)
Friction Losses In Pipe; C = 100
2% Inch
FLOW
us
2.323 inside dia
2.469 inside dia

ielocit
f t per
sec
Velocit
head
ft
Head
loss
f t per
100 f t
.54
.67
.80
.94
1.07
.00
.01
.01
01
.02
.12
1.21
1.34
1.47
1.61
1.
Drilling Hydraulics
Whether a well is directional or nondirectional, the drilling mud and circulating
system are keys to its successful drilling and completion. Smith (1990) presents a
detailed discussion of drilling fluids and circulating system compone
Geologic Steering
Until relatively recently, it was easy to make a distinction between planning a well
trajectory and actually following it. We would develop a directional profile as part
of the well plan, and then go out and drill the well along this pre
Bit Selection
Fixed cutter (i.e., PDC and natural diamond) and rolling cutter bits (i.e., milled
tooth and tungstencarbide insert) are available for a wide range of rock types. In
general, PDC and natural diamond bits are most applicable to soft, unconso
Wireline Steering Systems
A wireline steering system consists of a bottomhole assembly that accommodates
a measurement probe run on wireline ( Figure 1 ). The probe employs
magnetometers to measure direction, and accelerometers to measure hole angle.
It a
Downhole Mud Motors
Downhole motors (commonly known as mud motors because they are
hydraulically driven by the circulating drilling fluid as it moves down the drill
string) have played an integral role in the advancement of directional drilling
technology