The document discusses velocity tools used in production logging, specifically focusing on spinners which measure fluid flow velocities. It provides background on spinners, including their history, types, basic working principles, and challenges in measurement. Graphical methods for interpreting spinner log data are also explained.
Drilling fluids are absolutely essential during the drilling process and considered the primary well control.
Know more now about such a very important component of the drilling process.
Drilling fluids are absolutely essential during the drilling process and considered the primary well control.
Know more now about such a very important component of the drilling process.
Skin factor is a dimensionless parameter that quantifies the formation damage around the wellbore. it also can be negative (which indicates improvement in flow) OR positive (which means formation damage exists). Positive skin can lead to severe well production issues and thus reducing the well revenue
Production optimization using gas lift techniqueJarjis Mohammed
After completed the drilling, set the tubing and completed the well successfully, Petroleum engineers realize that the hydrocarbon fluid won't lift up from bottom hole to the surface by its reservoir drives which are mainly gas cap or water drive. Simply the gas lift technique is to reduce the density of hydrocarbon fluid inside the well to lift it to the surface by injecting compressed gas.
ADVANCED PRODUCTION LOGGING, CASED HOLE & PRODUCTION LOG EVALUATIONpetroEDGE
The following agenda is based on three morning and three afternoon sessions daily, each session approximately one to 1-1/4 hours in length. These sessions are labelled M1, M2, M3, and A1, A2, and A3 respectively. Note that class problems (PROBLEMS), movies (MOVIES), and guest lecturers (GUEST) have been highlighted. Numerous log examples for class discussion are also presented throughout the course.
wireline sampling or testing tools and bore hole televiewer are a formation testing tools.they help in understanding and evaluating the formation fluid ,composition ,rock type(hard or soft),mud cake thickness etc better .FT,FIT,RFT help in bringing out the formation fluid to the surface and test in the laboratory to conduct a detailed study on fluid type.
production engineering 2 topic.
which includes the production logging tools, its application, categories of application and also some uses of the log with example in the practical life and physics.
This 5 day training course is designed to give you a comprehensive account of methods and techniques used in modern well testing and analysis. Subsequently to outlining well test objectives and general methodologies applied, the course will provide real case studies and practice using modern software for Pressure Transient Analysis. These exercises will demonstrate clearly the limitations, assumptions and applicability of various techniques applied in the field.
All hydrocarbon reservoirs are surrounded by water-bearing rocks called aquifers which they effect on reservoir performance. it's a key role for production evaluation and therefore it should be managed.
introduction to ESP (electrical submersible pump), working principle of ESP (electrical submersible pump), Application of ESP (electrical submersible pump), Uses of ESP in Oil Well, Specification of ESP (electrical submersible pump), New varieties of ESP (electrical submersible pump).
Surge Pressure Prediction for Running Linerspvisoftware
This white paper will review the engineering analysis behind trip operations for different pipe end conditions. The author will discuss the controlling parameters affecting surge pressure using SurgeMOD. There are 2 aspects of the surge and swab pressure analysis: one is to predict surge and swab pressure for a given running speed (analysis mode), while the other one is to calculate optimal trip speeds at different string depths without breaking down formations or causing a kick at weak zone (design mode). This article will address both issues. Examples of running liners in tight tolerance wellbore will be analyzed.
Skin factor is a dimensionless parameter that quantifies the formation damage around the wellbore. it also can be negative (which indicates improvement in flow) OR positive (which means formation damage exists). Positive skin can lead to severe well production issues and thus reducing the well revenue
Production optimization using gas lift techniqueJarjis Mohammed
After completed the drilling, set the tubing and completed the well successfully, Petroleum engineers realize that the hydrocarbon fluid won't lift up from bottom hole to the surface by its reservoir drives which are mainly gas cap or water drive. Simply the gas lift technique is to reduce the density of hydrocarbon fluid inside the well to lift it to the surface by injecting compressed gas.
ADVANCED PRODUCTION LOGGING, CASED HOLE & PRODUCTION LOG EVALUATIONpetroEDGE
The following agenda is based on three morning and three afternoon sessions daily, each session approximately one to 1-1/4 hours in length. These sessions are labelled M1, M2, M3, and A1, A2, and A3 respectively. Note that class problems (PROBLEMS), movies (MOVIES), and guest lecturers (GUEST) have been highlighted. Numerous log examples for class discussion are also presented throughout the course.
wireline sampling or testing tools and bore hole televiewer are a formation testing tools.they help in understanding and evaluating the formation fluid ,composition ,rock type(hard or soft),mud cake thickness etc better .FT,FIT,RFT help in bringing out the formation fluid to the surface and test in the laboratory to conduct a detailed study on fluid type.
production engineering 2 topic.
which includes the production logging tools, its application, categories of application and also some uses of the log with example in the practical life and physics.
This 5 day training course is designed to give you a comprehensive account of methods and techniques used in modern well testing and analysis. Subsequently to outlining well test objectives and general methodologies applied, the course will provide real case studies and practice using modern software for Pressure Transient Analysis. These exercises will demonstrate clearly the limitations, assumptions and applicability of various techniques applied in the field.
All hydrocarbon reservoirs are surrounded by water-bearing rocks called aquifers which they effect on reservoir performance. it's a key role for production evaluation and therefore it should be managed.
introduction to ESP (electrical submersible pump), working principle of ESP (electrical submersible pump), Application of ESP (electrical submersible pump), Uses of ESP in Oil Well, Specification of ESP (electrical submersible pump), New varieties of ESP (electrical submersible pump).
Surge Pressure Prediction for Running Linerspvisoftware
This white paper will review the engineering analysis behind trip operations for different pipe end conditions. The author will discuss the controlling parameters affecting surge pressure using SurgeMOD. There are 2 aspects of the surge and swab pressure analysis: one is to predict surge and swab pressure for a given running speed (analysis mode), while the other one is to calculate optimal trip speeds at different string depths without breaking down formations or causing a kick at weak zone (design mode). This article will address both issues. Examples of running liners in tight tolerance wellbore will be analyzed.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Effect of tip clearance on performance of a centrifugal compressoreSAT Journals
Abstract The centrifugal compressor is to study the effect of tip clearance on the performance characteristics and the wall static pressure for a different flow co-efficient. The method of testing the compressor is run at a constant speed at 2000rpm. The tip clearance is varied by using spacers. The volume flow rate is varied with the help of throttling device to conduct the performance test. The performance characteristic of the centrifugal compressor showing the variation of discharge pressure with volume flow rate is plotted. Obtaining the performance characteristics showing the variation of discharge pressure with volume flow rate for different tip clearance, viz. =2.2%, 4%, 6.1% and 7.9%. Measurement of periodic pressure at various tip clearance viz. =2.2%, 4%, 6.1% and 7.9%. For each tip clearance pressure measured in radial location of impeller at 6 positions for different flow co efficient values. Five flow coefficients viz., ф =0.40, =0.34 (both above design flow), =0.28 (near design flow), =0.21=0.18 (both below design flow) and four values of non-dimensional tip clearance viz., =2.2%, 4%, 6.1% and 7.9%, are chosen for experimental work. The objective of the research work is to measure the periodic variation static pressure on the casing over the rotor at different values of tip clearance and flow coefficients. With the availability of these data, it is possible to improve the tip clearance flow in centrifugal compressor.
Flow analysis of centrifugal pump using CFX solver and remedies for cavitatio...IJERA Editor
In this scholarly thesis pertinent to the working of centrifugal pump, a CFD solver namely CFX is employed in order to simulate fluid flow characteristics with well-defined constraints and boundary conditions defining the problem. Stringent solid model is meticulously prepared encompassing the present day usage and constructional features of a centrifugal pump and is constrained with various boundary conditions having fixed domain in order to evaluate plots and results. To spearhead and facilitate this analysis program a numerical approximation tool with high degree of convergence rate called ANSYS 15.0 software is used. The ASNYS software avoids tedious calculations presumably impending in the design procedure and uses ultimate numerical tool to approximate the solution of the partial differential equations associated with continuity, momentum and energy phases of a flow problem in a 3-D model. This exquisite feature of ANSYS enables designer to optimize the design procedure in an iterative manner based on the final plots of post-processing phase. In addition, the scholarly writing also constitutes the appraisal of the most debilitating and painstaking problem retarding the efficiency of the centrifugal pump known as cavitation. Possible remedies for overcoming this problem will be indirectly inferred from the various plots and figures derived from the post-processing phase of the design process.
The effect of rotational speed variation on the velocity vectors in the singl...IOSR Journals
The current investigation is aimed to simulate the three-dimensional complex internal flow in a
centrifugal pump impeller with five twisted blades by using a specialized computational fluid dynamics (CFD)
software ANSYS /FLUENT 14code with a standard k-ε two-equation turbulence model.
A single blade passage will be modeled to give more accurate results for velocity vectors on (blade, hub, and
shroud). The potential consequences of velocity vectors associated with operating a centrifugal compressor in
variable rotation speed.
A numerical three-dimensional, through flow calculations to predict velocity vectors through a
centrifugal pump were presented to examined the effect of rotational speed variation on the velocity vectors of
the centrifugal pump . The contours of the velocity vectors of the blade, hub, and shroud indicates low velocity
vectors in the suction side at high rotational speed (over operation limits )and the velocity vectors increases
gradually until reach maximum value at the leading edge (2.63×10 m/s) of the blade
Butterfly valves are widely used in hydro power plants to regulate and control the flow
through hydraulic turbines. That’s why it is important to design the valve in such a way that it can give
best performance so that optimum efficiency can be achieved in hydraulic power plants. Conventionally
that the models of large size valves are straight in the laboratory to determine their performance
characteristics. This is a time consuming and costly process. High computing facility along with the use
of numerical techniques can give the solution to any fluid flow problem in a lesser time. In this research
work flow analysis through butterfly valve with aspect ratio 1/3 has been performed using
computational software. For modelling the valve ICEM CFD 12 has been used. Valve characteristics
such as flow coefficient and head loss coefficient has been determined using CFX 12 for different valve
opening angle as 30°,60°,75°, and 90° (taking 90°as full opening of the valve) for incompressible fluid.
Value of head loss coefficient obtained from numerical analysis has been compared with the
experimental results.
The effect of rotational speed variation on the static pressure in the centri...IOSR Journals
The current investigation is aimed to simulate the three-dimensional complex internal flow in a
centrifugal pump impeller with five twisted blades by using specialized computational fluid dynamics (CFD)
software ANSYS /FLUENT 14code with a standard k-ε two-equation turbulence model.
A single blade passage will be modeled to give more accurate results for static pressure contours on (blade,
hub, and shroud). The potential consequences of static pressure associated with operating a centrifugal
compressor in variable rotation speed.
A numerical three-dimensional, through flow calculations to predict static pressure through a
centrifugal pump were presented to examined the effect of rotational speed variation on the static pressure of
the centrifugal pump . The contours of the static pressure of the blade, hub, and shroud indicates negative low
static pressure in the suction side at high rotational speed (over operation limits )and the static pressure
increases gradually until reach maximum value at the leading edge (6×105 Pa) of the blade.
Investigation of effect of pump rotational speed on performance and detection...Mustansiriyah University
Cavitation is an essential problem that occurs in any pump. It highly contributes to deteriorating the performance
of the pump. In industrial applications, it is important to detect and decrease the effect of the cavitation in pumps.
In this work, detecting and diagnosing the cavitation phenomenon within centrifugal pumps using vibration
technique was investigated. The results obtained for vibration signal in both time and frequency domains were
analysed in order to gain a better understanding about the detection of cavitation in the pumps in question. The
effect of different operating conditions including various flow rates and pump rotational speeds related to the
cavitation were measured. Different statistical features in time domain analysis (TDA) and also the Fast Fourier
Transform (FFT) technique for frequency domain analysis (FDA) were applied.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Effect of flow coefficient and loading coefficient on the radial inflow turbi...eSAT Journals
Abstract
Before attempting to the design of radial inflow turbine, some of the techniques used to describe and present the effect of coefficient
on geometry, need to be appreciated. The user of turbine will generally require parameters which readily describe the overall
dimension of the machine so that assessments and comparisons can be easily made. The designer requires parameters which will
enable him to select the correct machine and make valid comparisons between competing designs. This allows the designer to
compute more easily the dimension of the machine at different coefficient, to assess the performance of a range of geometrically
similar machines. A paper describes the basic design parameters and effect of coefficient on radial inflow turbine impeller geometry
for 25kW application.
Index Terms: radial turbine design, flow and loading coefficient
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
IRJET-Effect of Horizontal Perforated Baffle on Sloshing in Partly Filled Tan...
Spinner velosity tool
1. STID 92250744
Velocity Tools in Production Logging.
A. Nasirisavadkouhi, International Campus of Sharif University of Technology
Winter 2015
This paper was prepared for the advanced well-log course held by Dr Saeed Shad at SUT_international Campus. The template of the paper is based on the latest SPE
standards therefore the pictures can be found at the end of the paper.
Abstract
Production logs are a record of one or more in-situ measurements that describe the nature and
behavior of fluids in or around the borehole during production or injection. The instrument
''spinner'' which is a device for measuring in situ the velocity of fluid flow in a production or
injection well based on the speed of rotation of an impeller, was introduced in this paper. Its history
and its types were mentioned. Then I discussed some concepts of its working and the reasons
behind it. Eventually a method of graphical spinner log interpretation was explained.
Fundamentals of Production Logging
The aim of production logging is to determine where the oil and gas and water are coming from in a
producing well or to determine where the gas or water is going to in an injection well. Because the
radial influx (or outflux) of these phases into the borehole cannot be directly measured, production
logging looks for intervals of stable or unchanging flow rate (q) and then calculates the differences
between adjacent stable intervals. From a few basic sensors, production logging tools have evolved
to a family of tools each with sensors designed to make measurements that, once interpreted
together, provide accurate flow rates for multiple phases and determine precisely where the various
fluids are entering (or exiting) the borehole. This development and application of new production
logging technologies is much needed, as well trajectories continue to grow in complexity,
progressing from vertical to deviated and horizontal and posing new challenges in completion
design and flow assurance. Downhole separators and positive displacement meters are not used to
measure the stable downhole flow rates; instead, velocities, areas, void fractions, and other indirect
attributes of the flow rate must be measured. Most of the measurements available have limited
ranges within which a calibrated response can be expected. It would be fair to say that the task of
converting downhole measurements into a multiphase flow rate and then accurately determining
where the various fluids are entering the borehole presents a challenge, a nontrivial task, or to use
plain, noneuphemistic language, a problem. The objective of this paper is to familiarize readers with
this tool and moreover to help them address the difficulties production logging faces in this area.
Therefore, this paper reviews the concepts with regards to the function of the Spinner.
The History and Evolution of the Spinner
As described in Bonet (Pat. US3,630,078) one of the most successful techniques presently
employed for determining the flow rate of fluids flowing in a well bore is to successively pass a so-
2. called "spinner-type" flowmeter tool at selected constant speeds through the fluid-filled well bore.
By successively recording the resulting rotational speeds of the flowmeter spinner at the
corresponding depth locations of the tool, a continuous flow survey or fluid-velocity log will be
obtained from which the flow rates of the well bore fluids at different depth intervals of the well
bore can be readily determined. Thus, where the well being surveyed is a production well having
two or more producing intervals, the resulting log will clearly indicate the respective velocities or
flow rates of the connate fluids which are being produced from each of the several producing
intervals. On the other hand, where the well is an injection well in which fluids are being injected
simultaneously into two or more formation intervals, the resulting flow survey will show what
portion of the injection fluid is entering each formation interval. Those skilled in the art will, of
course, appreciate that the rotational speed of the spinner in a flowmeter of this nature is simply a
linear function of the apparent or relative velocity of the well bore fluids in relation to the tool.
Thus, at low flow rates, the spinner will inherently turn at correspondingly-low speeds so long as
the well bore fluids are moving at a sufficient velocity to still turn the spinner. It is apparent,
therefore, that for a given spinner, the minimum "operating threshold" for such a flowmeter is
directly related to the amount of rotational friction which must be overcome before the spinner can
turn. Accordingly, as fully explained in the Bonnet, it was found that the unique magnetic
suspension arrangement shown there significantly reduced the static and dynamic friction affecting
the rotation of the flowmeter spinner. Although flowmeters arranged in accordance with the Bonnet
patent have met with considerable success, it has been found nevertheless that their loose-fitting
magnetically-suspended spinners become unreliable, if not ineffective, in substantially deviated or
non-vertical well bore interval. Attempts to use bushings or bearings of different types for
maintaining these spinner shafts coaxially centered in the tool have not been too successful,
however, in view of the additional friction. Moreover, fluid-borner debris such as sand grains or
other solid particles will often enter the clearance spaces around or in such bearings and impair, if
not totally disrupt, the operation of these bearings as well as other closely fitted movable elements
of the flow meter. Eventually innovations were introduced by (Anderson et al. US3,954,006) the
first results are shown in (Fig 2) . Nowadays turbine, or spinner, flowmeters are used extensively
within industry with small to negligible errors, the situation is very different in oilfield applications.
The fullbore spinner does not, as its name suggests, cover the entire pipe cross section (Fig. 3).
Typically a fullbore spinner sweeps only about 40% of the casings cross-sectional area. In addition,
the blades do not have a progressive pitch (as on a ship's propellers and in gas turbines) because the
requirement to collapse down to a diameter of 1 11/16
in precludes anything more complicated than a
flat spinner blade. The continuous, or tubing, spinner has a progressive-pitch spinner, which is more
effective at extracting energy from the well fluids (and therefore reducing the spinner threshold,
which is the minimum velocity needed to start the spinner turning) (Fig.4). Unfortunately, the much
reduced spinner diameter more than negates the effect of the improved blade profile, and the
threshold velocity of a standard tubing spinner is about 3 times higher than that of a fullbore
spinner.
The Flow Scanner mini spinner (Fig.5) is used in an array of five mini-spinners recording velocities
on the vertical axis of the pipe, from the bottom to the top. This arrangement is discussed in detail
for the Flow Scanner horizontal and deviated well production logging system (see the
"Fundamantals of production logging'' Ch.12.Flow Scanner Interpretation, Schlumberger). A change
of bearing technology together with the progressive pitch of a tubing spinner delivers a spinner
threshold comparable to that of a fullbore spinner.
Theoretical spinner response model
Consider the response of an ideal spinner flowmeter (Fig.6). The spinner speed in revolutions per
second (rps) is directly proportional to the fluid velocity passing through the spinner. The slope of
the response curve, measured in rps/ft/min [rps/m/min],comes directly from the spinner pitch
measured in inches [centimeters].
Once friction in the bearings is included, the response becomes a little more complicated, with two
3. response lines, one for positive spinner readings and a second for negative spinner readings. There
is now a range of low fluid velocities where the spinner does not turn because the spinner torque is
smaller than the bearing friction. Close inspection of the response lines in Fig.6 shows a small curve
at low spinner speeds owing to the action of static friction (stiction), viscosity effects, or both. To
avoid the complications arising from nonlinear spinner response, near-zero spinner readings are
discarded if they look at all suspicious. Increasing the viscosity of the fluid passing through the
spinner produces some unusual results. The threshold first increases and then decreases while the
spinner slope changes by about a factor of 5 or more. Figures.7 and .8 show the results of
previously unpublished experimental data from the Schlumberger Gould Research Center.
Changing the density of the fluid passing through the spinner (e.g., from liquid to gas) also
increases the size of the low-velocity region where the spinner does not turn but should not
significantly change the spinner response slope (Fig. 9).
However, changing the fluid from liquid to gas causes a big change in the pseudo-Reynolds number
(created using the tool velocity) and makes the creation of turbulence and vortices much easier, thus
leading to the situation of (Fig. 10).
Nℜ pseudo
=
ρ.v .d
μ
where: v: tool velocity, m/s ρ=gasdensity ,kg/m
3
d=hydraulic diameter ,m μ=dynamic viscosity ,Pa.s
On the left of (Fig. 10) is an upward-moving tool (equivalent to a negative fluid velocity)
generating vortices that travel down and confuse the spinner. Behavior like this creates asymmetric
spinner slopes and thresholds. The effect can be expected to be bigger in gas wells, but it is still
present in water and the lighter oils. In the middle and on the right of (Fig. 10) is the effect of the
spinner cage stirring up the flow. To a first-order approximation the effects seem to be equal for
flow from above and flow from below.
Practical spinner response model
The theoretical spinner response model described in the previous section is too complicated for
everyday use. Instead, some approximations are introduced until the model of (Fig. 11) is reached.
This shows a spinner in an unknown fluid as having a positive and negative spinner slope and a
positive and negative spinner threshold. Because these four parameters can change with velocity,
fluid density, fluid viscosity, casing diameter, and other conditions, the model needs judicious
updating over an interpretation interval.
Spinner interpretation —Initial laboratory characterization
The first approach (Meunier et ah, 1971) to calibrating the spinner involved laboratory
characterization and the creation of interpretation nomograms (Fig. 12).
The laboratory-determined spinner threshold and spinner pitch were combined with a stationary
spinner reading, velocity profile viscosity model, and the pipe internal diameter to deliver a
downhole flow rate. Unfortunately, the log analyst did not often have reliable downhole viscosity
information, so measurements of the spinner threshold in the laboratory were rarely representative
of the field, and logs versus depth could not easily be processed. Since tool speed cannot be
measured downhole, as a proxy the cable velocity at surface is used. Typically cable speeds of 30,
60, and 90 ft/min [10, 20, and 30 m/min] are used, but for unstable wells additional speeds are
added to average out the variations. For high-velocity gas wells, top speeds of 120-150 ft/min [40-
50 m/min] are used to better define the positive spinner intercept.
In situ spinner calibration
Because it is impractical to vary the downhole fluid velocity while measuring the spinner rps, the
problem of spinner characterization (usually known as calibration) is approached from a different
direction. Instead of varying the fluid velocity, the tool is moved up and down at different speeds
4. and the spinner rps plotted versus tool speed.
In the absence of any kind of downhole velocity or downhole depth measurement, the tool velocity
is inferred from the cable velocity as it leaves the drum at surface. Fortunately, under steady-state
conditions the velocity at surface is very close to the downhole tool velocity. However, under
transient conditions as the tool accelerates from rest or slows to a halt, the tool velocity cannot be
expected to accurately match the cable velocity at surface. As a rule of thumb, traversing a 30-ft
[10-m] interval above the top perforation and below the deepest perforation allows the tool to
achieve a steady velocity before logging the zone of interest.
In a zero-flow environment it is possible to determine the positive and negative spinner slopes and
the positive and negative spinner thresholds (Fig. 13). But where does a zero-flow environment
exist? Shutting in the well at surface does not guarantee zero flow because there may be cross flow
between zones. Above the top perforation, after the well has been shut in for many hours, there
should be no flow, but in the time available for production logging there may be wellbore storage
(unlikely) or liquid fallback from the tubing that extends to surface. Although it is safer to assume
that there is no flow below the deepest perforation (in the absence of casing plugs isolating deeper
zones), the fluid density and viscosity below the deepest perforation are often unrepresentative of
the fluid density and viscosity flowing in the well (the fluid for which the spinner calibration is
intended). Usually the best way to identify a zero-flow region is to refer to the temperature log and
identify what appears to be a geothermal gradient because geothermal gradients are incompatible
with fluid movement. The spinner calibration in (Fig. 14) corresponds to a small positive velocity
(down flow) but this analysis can be delivered with confidence only after inspecting the temperature
log in (Fig. 15).
The log in (Fig. 15) shows cable velocity, depth, spinner rps, the extent of the perforated intervals in
red, spinner calibration zone in yellow, rate calibration zones in gray, pressure, temperature, and
density (indicating a water-filled borehole). The steep change in temperature at about 3,900 ft
shows where the cooler cross flowing water is lost into a perforation (indicated in red) and the
geothermal gradient is recovered.
Recirculation and the spinner
In anywhere from 5° to 75° deviation, a low mixture velocity combined with a high slip velocity
produces gravity segregation of the phases, giving rise to large high-side velocities, significant
shear between light and heavy phases in the pipe, and finally a downflow of the heavy phase on the
low side of the pipe (Fig. 16 ). A centered spinner tries to average the mixture of velocities passing
through the swept area of the blades but generally returns a velocity that is too low if not actually
negative. A poorly centralized spinner, lying closer to the low side of the pipe, returns an answer
still more heavily weighted for heavy-phase recirculation.
Increasing the diameter of the spinner blades reduces the size of the errors and is the simplest way
of improving data quality under these conditions. While recirculation normally occurs with gas or
oil bubbling up through water, the inverse situation, of water falling back through oil or gas, is often
seen when a well has just been shut in. In these cases the spinner sees an erroneous uphole flow
rate.
Diverter flowmeters
Another approach to handling the problems of recirculation is use of the diverter flowmeter.
Because recirculation requires a low mixture velocity, the diverter, or petal basket (Fig. 17),
flowmeter funnels the flow of the well through a 1- to 1 ½ in diameter tube in which a spinner
velocity is recorded. If run in a 7-in completion the diverter flowmeter increases the velocity by
about 20 times and therefore reduces the poorly defined threshold for recirculation effects to one
twentieth. However, once the diverter is deployed the diverter flowmeter tool can only be used to
make stationary measurements. This means that the accelerated flow passing through the diverter
must exceed the spinner threshold (which is of the order of 15 ft/min for the small spinner used). In
addition, the in situ spinner calibration of the slope and threshold must be made with the flowmeter
5. closed and in a different flow regime from that being used for the station measurements.
Nevertheless, the diverter flowmeter is currently the least bad approach to measuring velocity in the
presence of recirculation.
Graphical interpretation techniques
In the past, graphical techniques for interpreting spinner data were very popular. One elegant
approach is still seen in production log interpretation manuals. In (Fig.18), after the various stable
interval responses are plotted together with a zero-flow response, the reading line for the zero tool
velocity spinner is projected right, across to the zero-flow line, from which a vertical line is dropped
down to the horizontal axis, which delivers the fluid velocity. Increasing the slope of the zero-flow
line by the reciprocal of the velocity profile correction factor automatically corrects for the velocity
profile across the pipe. This technique assumes that the zero-flow spinner response slope and
threshold are applicable to all the stable intervals above. In practice this is true only for well-
behaved monophasic wells with a clean, uncontaminated zero-flow region at the bottom. This
plotting technique is no longer used commercially.
References
Colin Whittaker ''Fundamantals of production logging'' ,2012, Schlumberger Technology Corporation.
Jean-Loup Bonnet, ''MAGNETIC SUSPENSION FLOWMETER'' Verrieres-le-Buisson, France, Schlumberger
Technology Corporation, Oct. 31, 1969, United States Patent Nu.3,630,078
Meunier, D., Tixier, M.P., and Bonnet, J.L.: "The Production Combination Tool, A New System for Production
Monitoring," Journal of Petroleum Technology (May 1971), 603-613.
Ronald A. Anderson; James J. Smolen, both of Houston, Tex. ''methods for determining velocities and flow rates of
fluids flowing in well bore'', Schlumberger Technology Corporation, May 4, 1976,United States Patent Nu.3,954,006.
6. Figures.
Figure 1. The principle of production logging Figure 2. The first result of Spinner log
i. shows a typical flowmeter as it, will appear
during the practice of the methods of the present
invention in a. conventional multi-zoned production
well;
ii , iii. respectively depict typical flow
measurement logs representative of what may he
obtained during the practice of the present invention in
a well bore such as shown in (I) with these measure
ments again being presented in (iii) as they might
appear when uniquely combined on a composite record
for presenting a continuous flow profile of the
wellbore;
i ii iii i
Figure.3 Fullbore spinner schematic Figure 4. Continuous, or tubing, spinner.
7. Figure 5. Flow Scanner minispinner. Figure 6. Spinner response with friction and stiction.
Figure 7. Spinner response to increasing viscosity.
Figure 9. Spinner response to decreasing density.
Figure 8. Spinner response to increasing viscosity, amplified scale
8. Figure 10. Fluid turbulence and the fullbore spinner. Figure 12. Spinner interpretation nomogram (Meunier et at, 1971)
Figure 11. Approximation to a spinner response. Figure 13. Zero-flow spinner calibration.
Figure 14. Ambiguous near-zero spinner calibration.
9. Figure 15. Near-zero spinner calibration plot data.
In the absence of any kind of downhole velocity or downhole depth measurement, the tool velocity is inferred from the cable velocity as it
leaves the drum at surface. Fortunately, under steady-state conditions the velocity at surface is very close to the downhole tool velocity.
However, under transient conditions as the tool accelerates from rest or slows to a halt, the tool velocity cannot be expected to accurately
match the cable velocity at surface. As a rule of thumb, traversing a 30-ft [10-m] interval above the top perforation and below the deepest
perforation allows the tool to achieve a steady velocity before logging the zone of interest.
10. Figure 16. Three-dimensional axial velocity distribution in recirculation. Figure 16. Diverter, or petal basket, flowmeter
Figure 17. Graphical techniques for computing the mixture velocity.