The research paper published by IJSER journal is about Laboratory Study of Effect Of 1.0mm-Sawdust With Various Types of Viscosifier Additives On Properties of Oil-Based Drilling Mud 1

ISSN 2229-5518

Laboratory Study of Effect Of 1.0mm-Sawdust With Various Types of Viscosifier Additives On Properties of Oil-Based Drilling Mud

Adebayo, Thomas Ayotunde Aria Osiwi Nwafor-orizu Ezejanu N.

Abstract- Laboratory application of sawdust in oil-based mud was carried out. 1.0mm sawdust sample was used as follow up to earlier experiments. Various viscosifier; bentonite, kaolin and starch were added to the mud samples. Results obtained gave good results for improvement in the density, initial and final gel strength and viscosities of the mud. This proved that sawdust associated with the viscosifier is a good gel and viscosity additives in oil-based mud. The

result obtained for the cake formation was not encouraging at 50oC and it was only at 70oC and with the addition of

combined kaolin and starch addition that an acceptable mud cake thickness was obtained. Other than this, it is either the mud cake formed is unstable or it is too thick in which either way will result into hole problem during well drilling

Index Terms— Sawdust, CO2 contamination, filtration loss, viscosity, mudcake, oil based mud.

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1 INTRODUCTION

Adebayo and Chinonyere in their research concluded that 1.0mm sawdust is the best, among other two sizes, filtrate control agent for a water-based drilling mud [1] and this was applied in this research on oil-based drilling mud.

This research finds application for the wood waste, sawdust and shavings, in drilling mud.

Aged sawdust was used since sawdust contains some amount of phenol in its fresh state but under rain condition or under running water, the phenol would have been leached by the rain [2].

Apart for the investigation of the effect of the sawdust

as a possible filtration control additive, further studies were also carried out to investigate the effect of the addition of three types of viscosifier; bentonite, kaolin and corn starch. this is because a drilling mud must, as a necessity, contain a viscosifier.

Viscosifiers were applied because earlier study indicated the need to add viscosifier to mud when sawdust is used as a filtrate control additive in water based mud [1].

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Adebayo Thomas A. is a staff of Petroleum Engineering Department, Covenant University, Nigeria. thomas_adebayo2001@yahoo.com Aria Osiwi & Nwafor-orizu Ezejanu are undergraduate students of

Petroleum Engineering Department, Covenant University, Nigeria.

The volume of the viscosifier used varies as stated in some earlier studies that more volume of unprocessed kaolin is required as a replacement for equivalent volume of bentonite [5].

2 METHODOLOGY

Aged sawdust was used and this was collected from sawmill and it is a mixture of three most popular west Nigerian woods: mahogany, Ipe and African blackwood. It was sieved and the approximately 1.0mm grade was chosen.
Fresh oil-based mud sample was prepared with
1.0mm sawdust added to the mud.
Different samples of the mud were prepared with bentonite, kaolin, starch and mixture of kaolin-starch as viscosifiers in accordance with research by Adebayo [4] [5].
The densities and pH of various samples were
measured.
Viscosities of the mud were measured together with the gel strength using viscometer.

The research paper published by IJSER journal is about Laboratory Study of Effect Of 1.0mm-Sawdust With Various Types of Viscosifier Additives On Properties of Oil-Based Drilling Mud 2

ISSN 2229-5518

The filtrate and mud cake thickness of the
various samples were measured using HPHT
filter press.

3 Results

The measurements of the various properties of prepared mud samples obtained were stated in Tables 1
to 5 while the graphical representations are as shown in
figures 1 to 7 below.
Figures 1 to 7 below graphically represented the measured and calculated properties of various samples of the oil-based mud with the various viscosifier additives.

9.6

9.5

9.4

9.3

9.2

9.1

8.9

8.8

9.5 9.52

9.3 9.29

9.04

20 17

0.4

49 46

23 21

Sawdust additive with no viscosifier sawdust with 5g bentonite 0

sawdust with 25g kaolin sawdust with 25g kaolin and 5g starch

sawdust with 5g cassava starch

Static gel …

Figure 1: pH measured for various mud samples With Various Viscosifier

Figure 3: Initial & Final Gel Strengths of Mud With Various Viscosifier

Volumes

9.8

9.7

9.6

9.5

9.4

9.3

9.2

9.1

8.9

9.2

9.4

9.7 9.7

9.6

350

300

250

200

150

100

120

217

250

296

0 0

Sawdust additive with no viscosifier sawdust with 5g bentonite

sawdust with 25g kaolin sawdust with 25g kaolin and 5g starch sawdust with 5g cassava starch

Apparent Viscosity Yield Points

Figure 2: Density of Mud With Various Viscosifier

Fig. 4: Apparent Viscosities and Yield Points of Mud With Various Viscosifier

The research paper published by IJSER journal is about Laboratory Study of Effect Of 1.0mm-Sawdust With Various Types of Viscosifier Additives On Properties of Oil-Based Drilling Mud 3

ISSN 2229-5518

10 8

4.5 3.5 6

5 Filtrates At 50 C

2.5

4.3

Filtrate water

1 0.8

0 0 0 0 0

Filtrate Oil

Fig. 5: Filtrates (water and oil) at 50oC Temperature.

50oC Mud thickness

Fig. 7: Mudcake Thickness For Various Sizes of Sawdust

Key: Fig. 3 to 7

15.4

10 8.6

11.5

14 13

12 11

Sawdust additive with no viscosifier sawdust with 5g bentonite

sawdust with 25g kaolin

sawdust with 25g kaolin and 5g starch

sawdust with 5g cassava starch

Filtrate water

Filtrate Oil

Fig. 6: Filtrates (water and oil) at 70oC Temperature.

4 Conclusions

The density graph, fig.2, indicated that addition of viscosifier caused a general increase in the density of the oil based mud. Fig.1 shows that while addition of bentonite caused an increase in the pH of the mud, addition of kaolin made the mud to have lower pH values while the addition of starch caused the greatest reduction in the pH values among the used viscosifier.
The initial and final gel strengths of the mud samples increased with addition of viscosifier. Bentonite caused a 200% increase in the initial gel strength while kaolin gave higher increase and addition of starch gave the greatest increase. Addition of starch to the mud with kaolin caused a depression in the value of the gel
strength. the final gel strength followed the same
partern as that of the initial gel strength.
Fig. 4 indicated that viscosity of the mud increased with the addition of viscosifier in the order of bentonite, kaolin, kaolin-starch and starch only. This proved that starch is a powerful viscosifier with an increase of almost 290%. The yield point also increased with addition of bentonite and kaolin respectively. The yield point for samples with starch additive was undeterminable with the percentage of oil in the mud sample.
Figs. 5-7 shows the effect of the viscosifier on sawdust filter control mud. At 50oC, samples with
kaolin additive gave lower filtrate volume while the one

The research paper published by IJSER journal is about Laboratory Study of Effect Of 1.0mm-Sawdust With Various Types of Viscosifier Additives On Properties of Oil-Based Drilling Mud 4

ISSN 2229-5518

with starch gave excessive filtrates. The filtrate given by sample with kaolin was lowest at 70oC followed by that of bentonite while the starch added sample gave too high filtrate values. The mud cake formed was not good with all the samples at 50oC except with the mud without viscosifier while the one with starch gave excessive cake that could create hole problems. At 70oC, the sample D with kaolin and starch additives gave reasonable mud cake thickness.

References

[1] Adebayo, Thomas Ayotunde and Chinonyere, Precious C., 2012, Application of Sawdust and shavings as filtrate loss additives in water-based mud, International Journal of Scientific and Engineering Research (IJSER) Volume 3, Issue 7, July (accepted for publication)
[2] Geoffrey Ian Miller , Making Use of Sawdust,
http://archive.suite101.com/article.cfm/organic/6
8287, May 8, 2001
[3] Gene Wengert, forum moderator http://www.woodweb.com/knowledge_base/Us es_for_shavings_and_sawdust.html#addyourco mment.
[4] Adebayo, Thomas A. and Imokhe Omolegho,
2011, Tiro (Antimony-Sulphide) And Potash As Local Substitutes To Imported Barite And Lignosulphate In Drilling Mud Weighting Additives, International Journal of Engineering and Technology, Vol.11, issue 3, June 10, pp138-
142.
[5] Adebayo, Thomas A. and Ajayi Sola, 2011, Unprocessed Ota Kaolin As A weighting Additive In Drilling Fluid, Asian Transactions On
Engineering (ATE), Vol.1, issue 3, pp. 23-26.

APPENDIX

Table 1: pH & Density Readings For Various Mud Samples

Table 2: 10secs & 10mins Gel Strength For Various Samples

	Initial gel strength lb/cu.ft	Final gel strength lb/cu.ft
Sample A	17	0.4
Sample B	41	16
Sample C	49	23
Sample D	46	21
Sample E	61	41

The research paper published by IJSER journal is about Laboratory Study of Effect Of 1.0mm-Sawdust With Various Types of Viscosifier Additives On Properties of Oil-Based Drilling Mud 5

ISSN 2229-5518

Table 3:Calculated Viscosities & Yield Point Values From Viscometer

Reading

Table 5: Filtrates of Samples at 70oC

Sample	Filtrate 70oC
Sample	water	oil
A	15.4	8.6
B	11.5	15
C	9	12
D	11	14
E	13	26

Table 4: Filtrates Measurement at 50oC

Table 6: Measured Mud Thickness For Various Samples

Adebayo and Precious are of the Department of Petroleum
Engineering, Covenant University, Nigeria