Assessing the impact of geochemical mechanism and interpolation factor selection on the precision of low-salinity waterflooding modelling: a comparative study

Figures & data

Figure 1. Relocation of the junction between Kr curves using schematic manipulation following LSWF.

Table 1. SARA components before and after distillation of oil.

	Saturates	Aromatics	Resins	Asphaltene
Before	54.03	32.16	11.69	2.12
After	54.95	32.94	12.03	0.08

Figure 2. Oil viscosity variation vs. pressure (a) and temperature (b).

Table 2. FW, Asmari water, and SW chemical composition (ppm).

	Na^+	K^+	Ca^2+	Mg^2+	Cl^−	SO4^2–	HCO3^2–	Total
Synthesized FW	27 950	43 800	8 000	1500	110 000	600	500	192 350
Asmari Water	27 970	43 810	8 020	1 480	110 000	600	500	192 380
Synthesized SW	24 000	12 000	1 100	800	1468	632	0	40 000

Table 3. mineralogy of the rock samples using XRD.

Dolomite	Calcite	Anhydrite	Quartz	Montmorillonite	Pyrite
62	14	11	7	4	2

Table 4. Core plugs’ petrophysical properties.

Core	L (mm)	Pore Volume (cc)	φ (%)	k (mD)	Swirr (%)
G-1	70	15.10	19.1	37.3	24.7
G-2	71	14.12	18.6	36.8	25.1
G-3	69	12.67	19.2	36.6	24.9
G-4	66	11.55	18.4	37.1	25.2

Figure 3. Schematic of the coreflood apparatus.

Figure 4. The schematic of the experimental setup for contact angle measurement.

Figure 5. The 3D view of the model.

Table 5. rock solution/precipitation reactions.

CaCO3(s) → Ca^2+ + CO^3–	Log k = −8.48
CaMg (CO3)2(s) → Ca^2+ + Mg^2+ +2CO2^−	Log k = −17.09
CaSO4(s) → Ca^2+ + SO2	Log k = −4.58

Table 6. Characteristics of modelling approaches.

Governing mechanism	Selected interpolation factor (IF)	IF value
fines migration	[Ca^2+]	N/A
rock dissolution/precipitation	total ionic strength (TIS)	0.2–0.9
multi-ion exchange (MIE)	[SO4^2–]	0.33–0.43

across various experiments.

Figure 6. Experimental results: (a) SW (b) LoSal-01 (c) LoSal-02 (d) LoSal-03.

Figure 7. ORF for LSWF with different salinities.

Table 7. PDIs’ concentration (ppm) and contact angle (degree) before and after LSWF.

		SW	LoSal_01	LoSal_02	LoSal_03
[SO4^2–]	Initial	632	225	112	45
	Final	281	100	50	20
[Ca^2+]	Initial	1100	112	57	22
	Final	480	50	25	10
[Mg^2+]	Initial	800	138	68	27.5
	Final	220	37.5	18.75	7.5
Contact Angle	Өi	135	133	138	131
	Өf	85	76	71	59

Figure 8. Modelling result of LSWF using fines migration mechanism: (a) SW (b) LoSal-01 (c) LoSal-02 (d) LoSal-03.

Figure 9. Modelling results of LSWF using rock dissolution/precipitation (a) SW (b) LoSal-01 (c) LoSal-02 (d) LoSal-03.

Figure 10. Relative permeability for rock dissolution/precipitation model: (a) SW (b) LoSal-01 (c) LoSal-02 (d) LoSal-03.

Figure 11. LSWF modelling using MIE mechanism: (a) SW (b) LoSal-01 (c) LoSal-02 (d) LoSal-03.

Figure 12. Oil and water relative permeability curves in the MIE model: (a) SW (b) LoSal-01 (c) LoSal-02 (d) LoSal-03.