Page 240 - Gas Wettability of Reservoir Rock Surfaces with Porous Media
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224 Gas Wettability of Reservoir Rock Surfaces with Porous Media
6.3.2.4 EVALUATION OF TEMPERATURE RESISTANCE
During the experimental process, the antiswelling height and rate at room
temperature and 110 C were measured. The result is shown in Fig. 6.15.
It can be seen from the experimental data that there is no difference in the
antiswelling effect before and after trapezoid protection agent A is processed at
110 C. It is applicable to high temperature reservoirs with low permeability.
6.3.2.5 EVALUATION OF DAMAGE CAUSED TO RESERVOIRS WHEN
TRAPEZOID PROTECTION AGENT A BECOMES ADSORBED ON THE ROCK
SURFACE, AND TREATMENT PERIOD EVALUATION
A core flow tester was used to evaluate the damage due to adsorption of trape-
zoid protection agent. The experiment was conducted based on the oil and gas
industry standard Article 6 of SY/T5971-94 Evaluation Method of Clay
Stabilizer for Water Injection. The experimental result is shown in Fig. 6.16 (the
core is taken from S2 upper layer of S56-10 well in Shengli Oilfield).
It can be seen from the experimental data that the trapezoid protection agent
A does not damage the reservoirs due to adsorption. When it is injected, the
permeability of cores increases slightly.
The core processed with adsorption damage was continually used in displace-
ment experiments. The antiswelling period evaluation was conducted by
injecting the modification water filtered at 2.2 μm, and expressed by changes
in permeability of core samples due to increase in injection volume. The
experimental results are shown in Fig. 6.17.
It can be seen from the experimental data that the trapezoid protection agent
A has better antiswelling functions. When the core is treated with 20 PV of
trapezoid protection agent A and 400 PV modification water is injected, the
100
80
Antiswelling rate (%) 60 After heating
Before heating
40
20
2 4 6 8 10
Concentration (%)
FIGURE 6.15
Evaluation of result with high temperature resistance of trapezoid protection agent A.
