Page 261 - Gas Wettability of Reservoir Rock Surfaces with Porous Media

Application of Gas Wettability CHAPTER 6 245

Spectrophotometry, and the experimental procedure for measuring oil
content in degreased oily cuttings is shown as follows:
a. The degreased cutting sample was smashed. The M(g) smashed cut-
ting sample was prepared and added to 20 M(g) anhydrous sodium
sulfate. It was then stirred evenly.
b. The mixed of solid powder i) was added into a conical flask, and
20 mL of green carbon tetrachloride (special for infrared oil content
analyzer) was added into the conical flask as well. The flask was then
sealed.
c. The conical flask was placed in a horizontal oscillator at a (the oscil-
lation frequency of 3.67 time/second, with oscillating time of
30 minutes).
d. The conical flash was then taken out and kept aside for half an hour.
The upper clear liquid was poured into a wide-mouthed bottle and
sealed.
e. The procedures iiBiv were repeated three times to extract the petro-
leum composition in the cutting samples.
f. A glass sand core funnel was used to pump the liquid in the wide-
mouthed bottle, and the liquid was then added into the volumetric
flask, at a volume of V(mL). Simultaneously, pure carbon tetrachlo-
ride was added and the volume was measured. The entire process
was conducted under anhydrous condition to avoid errors in the
experiment due to moisture.
g. The infrared oil content analyzer was adjusted to prepare a standard
solution and a standard curve. The liquid in the volumetric flask
with a volume of V(mL) was prepared and poured into a quartz ves-
sel, to measure the petroleum content. The measurement result is
P 0 (mg/L). If the measurement result exceeded the highest detection
limit of the apparatus, the liquid in the volumetric flask was diluted
by carbon tetrachloride and measured again. The dilution ratio is D.
h. The measured result of the above samples was calculated.
Calculation of petroleum content P 1 (%) in the residue of
degreased cuttings:
P 0 3 V 3 D
P 1 5 3 100%
M
wherein:
P 1 —Petroleum content of degreased oily cuttings, %.
P 0 —Concentration of the petroleum content measured by infrared
oil content analyzer, mg/L.
D—Dilution ratio of extract liquor, dimensionless.
V—Constant volume of extract liquor, mL.
M—Mass of oily cutting samples, g.
3. Degreasing experiment of oily cuttings
The experimental method for treating oily cuttings with a degreaser is
called a single variable method; i.e., if certain treatment conditions are