DATA ANAYSIS
Data Analysis with SPSS
Client name: Godwin
Field: Engineering
Aim and Objective
This project aims at studying the effect of locally processed micronized starch on the various rheological properties (such as apparent viscosity, yield point, gel strength etc) of the drilling mud. The study also seeks to study the effect of particle size reduction.
SECTION 1: T-TEST TO CHECK FOR THE EFFECT OF REDUCTION OF STARCH PARTICLE SIZE
Effect of particle size reduction
In this section we study the effect of particle size reduction on the rheological properties of drilling mud.
The following hypothesis will be tested for the effect of particle size reduction on the 3 rheological properties of drilling mud considered. The general hypothesis will be of the form shown below:
H0: There is no significant difference in the rheological properties of drilling mud when the particle size is reduced
H1: There is a significant difference in the rheological properties of drilling mud when the particle size is reduced
Decision Rule: If p-value is less than 0.05 (level of significance), reject H0, otherwise accept.
Group Statistics
Particle Size
N
Mean
Std. Deviation
Std. Error Mean
Plastic Viscosity
63 micron-
.20020
75 micron-
.20134
Apparent Viscosity
63 micron-
.55049
75 micron-
.46053
Yield Point
63 micron-
.74854
75 micron-
.65857
Independent Samples Test
t-test for Equality of Means
t
df
Sig. (2-tailed)
Mean Difference
Std. Error Difference
95% Confidence Interval of the Difference
Lower
Upper
Plastic Viscosity
4.451
70
-
.28393
-
Apparent Viscosity
3.512
70
-
-
Yield Point
2.535
70
-
.99701
-
Plastic Viscosity
The null and alternative hypotheses are postulated thus:
H0: There is no significant difference in the plastic viscosity of drilling mud when the particle size is reduced
H1: There is a significant difference in the plastic viscosity of drilling mud when the particle size is reduced
With a p-value less than 0.05 we reject H0 and conclude that the plastic viscosity of drilling mud is affected by the particle size, with the smaller particle size (63 micron) giving a higher Plastic viscosity than the particle size of 75 micron. The average difference in plastic viscosity between both particle sizes is 1.26 centipoise.
Apparent Viscosity
The null and alternative hypotheses are postulated thus:
H0: There is no significant difference in the apparent viscosity of drilling mud when the particle size is reduced
H1: There is a significant difference in the apparent viscosity of drilling mud when the particle size is reduced
The p-value for Apparent viscosity is 0.001(<0.05), hence we reject H0 and conclude that Apparent viscosity of drilling mud is affected by particle size reduction. The result shows that the smaller particle size gives a higher apparent viscosity than the large one with a mean difference of 2.52 centipoise. In other words, the reduced particle size led to increased apparent viscosity
Yield Point
The null and alternative hypotheses are postulated thus:
H0: There is no significant difference in the yield point of drilling mud when the particle size is reduced
H1: There is a significant difference in the yield point of drilling mud when the particle size is reduced
With a p-value less than 0.05 we reject H0 and conclude that the yield point of drilling mud is affected by the particle size, with the smaller particle size (63 micron) giving a higher yield point than the particle size 75 micron. The average difference in yield point of both particle sizes is 2.53 lb./100ft2.
With the above results we can infer that the smaller particle size enhances the rheological properties of drilling mud.
SECTION 2: ANALYSIS OF VARIANCE (ANOVA)
In this section we study the effect of locally processed micronized starch, temperature and concentration on the rheological properties of drilling mud. The Subject summary table below applies to all the rheological properties that follows:
Subjects Summary
Value Label
N
Concentration
1.00
0.5 gm
28
2.00
1.0 gm
28
3.00
1.5 gm
28
Starch Sample
1.00
Yam
24
2.00
Potato
24
3.00
Rice
24
4.00
CMC
12
Temperature
1.00
30 deg.
21
2.00
50 deg.
21
3.00
70 deg.
21
4.00
80 deg.
21
Plastic Viscosity
The effect of concentration, temperature and locally processed micronized starch on the plastic viscosity of drilling mud is tested using the table below; The decision rule described above still applies.
Tests of Between-Subjects Effects
Dependent Variable: Plastic Viscosity
Source
Type III Sum of Squares
df
Mean Square
F
Sig.
Corrected Model
502.696a-
.000
Intercept-
.000
CONC-
.000
STARCH-
.000
TEMPT-
.000
CONC * STARCH-
.851
.540
CONC * TEMPT
4.738
6
.790
.671
.674
STARCH * TEMPT
1.683
9
.187
.159
.997
CONC * STARCH * TEMPT
6.884
18
.382
.325
.993
Error-
Total-
Corrected Total-
a. R Squared = .922 (Adjusted R Squared = .821)
The following hypotheses are tested
TEST FOR SIGNIFICANCE OF CONCENTRATION LEVELS
H0: there is no significant difference in the plastic viscosity of drilling mud at the different concentration levels
H1: there is a significant difference in the plastic viscosity of drilling mud at the different levels of concentration
DECISION: since the p-value < 0.05 we reject H0 and conclude that the plastic viscosity of drilling mud indeed differ at different levels of concentration. In other words, when the concentration level is varied, it leads to significant changes in mud plastic viscosity.
TEST FOR SIGNIFICANCE OF STARCH USED
H0: the starch sample used does not significantly affect the plastic viscosity of drilling mud
H1: the starch sample used significantly affects the plastic viscosity of drilling mud
DECISION: since the p-value < 0.05 we reject H0 and conclude that the plastic viscosity of drilling mud is affected by the starch sample used.
TEST FOR SIGNIFICANCE OF TEMPERATURE LEVELS
H0: there is no significant difference in the plastic viscosity of drilling mud at the different temperatures.
H1: there is a significant difference in the plastic viscosity of drilling mud at the different temperatures
DECISION: since the p-value < 0.05 we reject H0 and conclude that the plastic viscosity of drilling mud indeed differ at different temperatures.
Post Hoc Tests
Here we probe into the variability between subjects that affected mud plastic viscosity, which in this case are all of them.
Concentration
Multiple Comparisons
Dependent Variable: Plastic Viscosity
LSD
(I) Concentration
(J) Concentration
Mean Difference (I-J)
Std. Error
Sig.
95% Confidence Interval
Lower Bound
Upper Bound
0.5 gm
1.0 gm
-1.1250*
.28996
.000
-1.7131
-.5369
1.5 gm
-1.9286*
.28996
.000
-2.5166
- gm
0.5 gm
1.1250*
.28996
.000
-
1.5 gm
-.8036*
.28996
.009
-1.3916
-.2155
1.5 gm
0.5 gm
1.9286*
.28996
-
1.0 gm
.8036*
.28996
.009
-
Based on observed means.
The error term is Mean Square(Error) = 1.177.
*. The mean difference is significant at the 0.05 level.
The column for p-value are all found to be less than 0.05, which implies that there is a significant difference in the plastic viscosity of drilling mud at all the concentration levels. This means that the plastic viscosity from 0.05-gram concentration differ from those of 1.0 and 1.5 grams, and that of 1.0 gram also differ from that of 1.5. The details of the mean difference in plastic viscosity is shown on the column for mean difference in the above table.
Starch Sample
Multiple Comparisons
Dependent Variable: Plastic Viscosity
LSD
(I) Starch Sample
(J) Starch Sample
Mean Difference (I-J)
Std. Error
Sig.
95% Confidence Interval
Lower Bound
Upper Bound
Yam
Potato
-.2292
.31319
.469
-.8644
.4060
Rice
.5625
.31319
.081
--
CMC
-5.9792*
.38358
.000
-6.7571
-5.2012
Potato
Yam
.2292
.31319
.469
-.4060
.8644
Rice
.7917*
.31319
.016
-
CMC
-5.7500*
.38358
.000
-6.5279
-4.9721
Rice
Yam
-.5625
.31319
.081
-1.1977
.0727
Potato
-.7917*
.31319
.016
-1.4269
-.1565
CMC
-6.5417*
.38358
.000
-7.3196
-5.7637
CMC
Yam
5.9792*
.38358
-
Potato
5.7500*
.38358
-
Rice
6.5417*
.38358
-
Based on observed means.
The error term is Mean Square(Error) = 1.177.
*. The mean difference is significant at the 0.05 level.
The row for CMC with p-values all less than 0.05 shows that the plastic viscosity of drilling mud when CMC is used differed significantly when the other starch samples were used. The other starch samples did not show significant difference in plastic viscosity, except for potato and rice with a p-value of 0.016, with potato giving a higher plastic viscosity by an average of 0.79 centipoise.
Temperature
Multiple Comparisons
Dependent Variable: Plastic Viscosity
LSD
(I) Temperature
(J) Temperature
Mean Difference (I-J)
Std. Error
Sig.
95% Confidence Interval
Lower Bound
Upper Bound
30 deg.
50 deg.
-.6905*
.33482
.046
-1.3695
-.0114
70 deg.
-1.2619*
.33482
.001
-1.9409
-.5829
80 deg.
-1.9524*
.33482
.000
-2.6314
- deg.
30 deg.
.6905*
.33482
.046
-
70 deg.
-.5714
.33482
.096
-1.2505
.1076
80 deg.
-1.2619*
.33482
.001
-1.9409
-.5829
70 deg.
30 deg.
1.2619*
.33482
.001
-
50 deg.
.5714
.33482
.096
--
80 deg.
-.6905*
.33482
.046
-1.3695
-.0114
80 deg.
30 deg.
1.9524*
.33482
-
50 deg.
1.2619*
.33482
.001
-
70 deg.
.6905*
.33482
.046
-
Based on observed means.
The error term is Mean Square(Error) = 1.177.
*. The mean difference is significant at the 0.05 level.
The result from the above shows that, there is no significant difference in the plastic viscosity of drilling mud at 500C and 700C with a p-value of 0.096 > 0.05. However, all other temperature levels differed significantly in plastic viscosity of drilling mud as they had p-values < 0.05.
FOR ILLUSTRATION PURPOSES, OTHER VARIABLES ARE TRUNCATED HERE
A sample Function written in R (for an iterative task)
Client name: Peter
Field: Mathematics
function(u.old,x.old,lambda.old,h,itra){
#h is d step size
#u.old is d initial guess
#x.old is d initial guess
#lambda.old is d initial guess
x.new