The Tiger Oil Co. Attachments: Results Homework Problems

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Collin Sharp
6 years ago
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1 The Tiger Oil Co. To: Andrew Wojtanowicz, Drilling Manager From: Kristen Barrett, Drilling Engineer Subject: Stuck Pipe Delays on Herget Field Wells, Exp #2 API Water Loss Date: September 1, 29 I do not agree with Mr. Wrong s suggestion to use an oil based mud system. It would be way too expensive and the risk of environmental contamination is way too high. My suggestion would be to use a mixture of Bentonite with CMC. As far as prices are concerned, the cheapest option is the bentonite and CMC mixture. Bentonite is $2/1lb sack, but oil based mud is $2/bbl. Although CMC is $1/1lb sack (very expensive), only a little bit is needed for each mixture so the prices aren t actually that bad. is $5/1lb sack (which is more than Bentonite), but it doesn t seem to work any better than Bentonite. As far as stuck pipe is concerned, Bentonite + CMC is also the best option. It created firm and thin cakes which would be perfect for avoiding stuck pipe., on the other hand, made thick cakes unless CMC was added. Also, the bentonite + CMC had the lowest water loss. It lost 5.2 ml in thirty minutes, and the attapulgite + CMC lost 14 ml of fluid in thirty minutes. In every respect, bentonite + CMC is the best option for this case. Attachments: Results Homework Problems

2 RESULTS 1.) Minutes Time Minutes Bentonite Bentonite API Filtrate Volume (ml) Bentonite + 2lb CMC + 2lb CMC Bentonite Bentonite Mud Cake Description Bentonite + 2lb CMC + 2lb CMC Firm X X X X X X Soft

3 Filtrate Volume (ml) Filtrate Volume (ml) Filtrate Volume vs. Time Minutes Bentonite Bentonite Bentonite + 2lb CMC + 2lb CMC Filtrate Volume vs. Time Minutes Bentonite Bentonite Bentonite + 2lb CMC + 2lb CMC According to the plots above, the theoretical relationship of filtrate volume compared to the square root of time holds true. There were only minor differences between the two different plots (time and time on the x axis). 2.) Spurt Loss V 3 = 2(V 7.5 V sp ) + V sp V 3 /2 = V 7.5 V sp + V sp /2 V 3 /2 - V 7.5 = V sp + V sp /2 V 3 /2 - V 7.5 = - (1/2) V sp

4 Filtrate Volume (ml) V 3 (2)V 7.5 = -V sp -V 3 + (2)V 7.5 = V sp This is the equation I used in my spreadsheet (below) to find V sp M i n Volume (ml) Bento Attapul nite + gite + Bentonite Bentonite 2lb 2lb Time CMC CMC 7.5 M i n Spurt Loss (ml) Mud Cake Thickness (inches) Extrapolated Spurt Loss 2 18 y = 87x y = 65x - 3 Bentonite Bentonite Bentonite + 2lb CMC y = 14x - 1 y = 9x y = 7.4x -.8 y = 3.2x time + 2lb CMC

The negative values obtained for the spurt loss results were due to the fact that before the first drop hits the measuring device, the filtrate must fill up the empty flow path.

5 The negative values obtained for the spurt loss results were due to the fact that before the first drop hits the measuring device, the filtrate must fill up the empty flow path. This means that the spurt loss that we measured in the lab is not actually 1% correct, but it is close enough for all practical purposes. My results indicate that Bentonite mixed with the CMC was the best clay to use for this experiment. I had assumptions about which clay mixture would work best before the experiment (since CMC is used to lower water loss, gel strength, and yield point), but the results proved that my assumptions were correct. Most of the mud cakes came out pretty firm with an approximate thickness of 3/32 but the and samples had thicknesses of 6/32 and 9/32, respectively. Please see the photo below to view the results of this experiment. As you can see, the first two attapulgite samples (bottom left and bottom center) are very thick. Once CMC was added to the attapulgite, the sample became very thin.

6 Homework Problems 2.4)a) 15 diameter hole 4 deep 1 ml API water Loss permeable 7% impermeable Time (min) Sqrt. Time Volume (ml) Conversions: Depth Dia. 4 ft *.3 = 12 ft 15 in (1 ft / 12 in)*(3.48cm / 1 ft) = 38.1 cm 12 ft * (3.48 cm / 1 ft) = cm Slope: m = 1 / 3 = API Water Loss: Vfiltrate = m * t = * = ml Afiltrate: 45 cm^2 Well Area: Awell = 2πrh = 2*π*(19.5)*(36576) = x1^6 cm^2 Volume Loss in Well after 24 hrs: V24 = (Awell / Afiltrate) * Vfiltrate = ( x1^6 / 45)* = 6.743x1^6 ml = 42.4 bbls Conversion: 6.743x1^6 ml (1 liter / 1ml)*(1gal / liter)*(1bbl / 42 gal) = 42.4 bbl

7 Volume (ml) Filtration Loss (bbls) Filtration Loss vs. Time Time (hrs) Volume vs. Time Time (min)

8 Volume (ml) Volume vs. Time Square Root of Time D. The API water test does not represent actual well conditions because it only operates under static conditions. The API test would be more accurate is mud was actual flowing past the cake during filtration like in real life wells. 2.5 Given: Time (min) Filtrate Volume (cm^3) V1 = 5cm^3 7.5 x Filter Press Area: 9cm^2 1 5 Vsp =.5 cm^3 Y = mx + b x = [(5 x) / ( 1-7.5)] +.5 V7.5 = 4.4 cm^3 -.5 = -x x V3 = 2 ( ) = x = 8.3 / = x V3 = 4.15 cm^3

Recommendations to Ensure Proper Cement Placement. Bryce London Tech. Professional-Lead

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