Drilling Fluids Lab – PETE 3265 – Section 1.

Spring 2015.

Lab partners: Briana Dodson, Aziz Al-Umairy

Report by: Alan Alexeyev

Experiments #7.1 and 7.2:

Design PHPA Mud and Comparing effect of cement

contamination on PHPA and Bentonite muds

Date performed: 4/8 and 4/15/2015

Date submitted: 4/22/2015

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Purpose:

The purpose of the two experiments was, firstly, to create a PHPA Mud with

compatible drilling properties of an 18 ppb Bentonite Mud. Secondly, to verify how robust

is the mud created in the first experiment under cementation contamination. The sub-

purpose was to learn how to create the experiments on our own, and that would prepare

us for the final experiment designed completely by our group.

Abstract:

This experiment prepared us for the design of our own mud. A little guidance was

given in terms of the quantities of the components that are required to create a mud. The

usual procedures that were learned from the previous labs were used. In the first part of

this two-week lab, the PHPA mud had to be created. PHPA stands for partially-hydrolyzed

polyacrylamide. Second part of the lab was to see how the created mud would withstand

the cement contamination. The results were recorded in the table and discussion will be

followed. This lab is essential to understating the importance of creating our own mud

that will help the different drilling operations under different conditions.

Introduction:

Introduction to mud contamination was given in the lab report #6. Today the task

was to create our own usually occurs in almost all of the wells drilled. It is a part of the

solids control for muds. PHPA is being added to the mud to treat it against the

contaminations.

PHPA is “a class of water muds that use partially-hydrolyzed polyacrylamide (PHPA)

as a functional additive, either to control wellbore shales or to extend bentonite clay in a

low-solids mud”. PHPA is supposed to seal small fractures and shale surfaces with a film

that retards dispersion and disintegration. PHPA mud is designed to be a shale-control

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mud. In low-solids muds, PHPA interacts with small concentrations of bentonite to link

particles together and improve rheology [2]. Having said that, PHPA is supposed to help

when mud is contaminated, and goes along with previous experiment when the

contamination methods and treatments were analysed.

Equipment and Materials used:

• Beakers, pH Meter, Blender, Marsh Funnel, Stopwatch, Mud balance by

OHAUS, OFITE – manufactured 8-speed Rotational Viscometer Model 800,

shearometer, OFITE filter press

• Water, Wyoming bentonite, Cement, caustic solution, PHPA, Bio-Lose.

• Towel, safety glasses, lab coat, gloves

Procedures:

For experiment 7.1, we started with 99g of bentonite and 1925mL of water. We used

bentonite data from lab 2 [3]. The procedures of mud preparation, water loss test, shear

strength test and others were described in the previous labs [3]. No chemical tests were

performed in this lab. For experimental mud, the following components were added:

2.75g of PHPA, 0.55g of Bio-Lose, and 0.55g of caustic solution. The results were recorded

in the tables below. To obtain the PHPA mud that would have similar properties of 18 ppg

bentonite mud we were experimenting with adding different ppb of bentonite to the

experimental mud. We ended up stopping at 13 ppb mud, as it was the closest.

In experiment 2 the task was to see how robust the created mud was under

contamination. When adding all the components the sum of them turned out to be

2000g. So 1% of that is 20g. Thus we used 20g of cement to contaminate it.

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Results:

Table 1. Lab #7.1 Experimental tries:

Bentonite Level, ppb θ600, cp θ300, cp 10 27 20 9 24 16 8 21 14

13 32 24

Water Loss, min Volume, mL 2.5 2.9 5 5

7.5 6

Mud Weight 9 ppg pH 8.6

Shear Strength 0

Table 2. Lab #7.2 Cement contamination:

PHPA Mud Mud #2: 1925g of water, 99g of bentonite, 20 g of cement

Water Loss, min Volume, mL Water Loss, min Volume, mL 2.5 3 2.5 12 5 4 5 17

7.5 5 7.5 21

Mud Weight 8.6 ppg Mud Weight 8.7 ppg pH 8.6 pH 7.7

AV 300 92 AV 300 30 AV 600 102 AV 600 35

10 sec GS 54 10 sec GS 7

Sheareometer 30 lb/100ft2 Sheareometer 18 lb/ft2

71.5𝑔𝑔 𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵 + 0.55𝑔𝑔 𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵 + 0.55𝑔𝑔 𝐶𝐶𝐶𝐶𝐶𝐶𝐵𝐵𝐵𝐵𝐵𝐵𝐶𝐶 + 2.75𝑔𝑔 𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 + 1925 𝑚𝑚𝐵𝐵 𝑤𝑤𝐶𝐶𝐵𝐵𝐵𝐵𝑤𝑤71.5 𝑔𝑔 𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵

2.6 𝑔𝑔𝐶𝐶𝑚𝑚3

+ 0.55𝑔𝑔 𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵2.13 𝑔𝑔

𝐶𝐶𝑚𝑚3+ 2.75𝑔𝑔 𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃

2685 𝑔𝑔𝐶𝐶𝑚𝑚3

+ 0.55𝑔𝑔 𝐶𝐶𝐶𝐶𝐶𝐶𝐵𝐵𝐵𝐵𝐵𝐵𝐶𝐶 + 1925 𝐶𝐶𝑚𝑚3 = 1.025

𝑔𝑔𝐶𝐶𝐶𝐶

= 8.55 𝑝𝑝𝑝𝑝𝑔𝑔

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Discussions:

In the experiment #7.1, the task was to create a PHPA mud compatible with a 18ppb bentonite mud that would have similar properties. To achieve that we were experimenting with the experimenting with the amount of bentonite to add, and ended when there was 13 ppb of bentonite in the mud, in addition to other components that were described in Procedures section. The results were very close to the 18ppb mud that was done in the previous labs, that’s why our group was confident to stop the experiment at that point. Designing this mud versus using just the original bentonite mud is perhaps needed to treat the contamination later.

The mud that was created in the experiment #2 was very-very viscous. It produced high viscosity values of almost 100 cp. Since it was viscous, it had a small water loss. Under cement contamination the viscosity values were 30-35 cp range for mud without PHPA and others. On the other hand, the water loss increased. It does verify the level of robustness; after the cement contamination the viscosity values were high. PHPA mud that was contaminated with only 1% of cement changed the properties dramatically. Perhaps the positive side of this is that if during the drilling the cement contamination is happening and the other muds can’t detect it, the PHPA mud can, seen from the high viscosity. PHPA could be a good tested for a contamination problems. That verifies the previous statement in Introduction that PHPA mud helps fight the contamination.

Safety Comments:

Regarding the safety, we were using the goggles, gloves, and lab coats. One needed to be careful when measuring, filling up the water to avoid spilling or break the equipment. Another important thing was to pour the fluids very carefully to avoid spillage, so that we will not lose any amount of fluids for further measurements.

Conclusions:

Upon concluding this experiment, our group learned how to create a mud with a minimum guidelines, and that would prepare us to create an experiment without any guidelines. The ideas about how to construct the mud, what components to add, and the ways how to treat the mud were learning and will be used on the final experiment.

References:

1. Pages 45-75. Adam T. Bourgoyne, Martin Chenevert, Keith Millheim, F.S. Young Jr., Applied Drilling Engineering, Vol.2, SPE, Richardson, TX. 1986

2. http://glossary.oilfield.slb.com/ 3. Drilling fluids lab 1, 2, 3, 4, 5, 6 by Alan Alexeyev. February – April 2015.

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