Experimental Investigation on the Influence of the Salinity Adsorption-Desorption Behavior of the Clay-based Rocks

The process of extracting oil from the ground is a tradeoff between revenue and costs. In the later production phase of an oil field, enhanced oil recovery (EOR) becomes a viable option in increasing dwindling production. Most common EOR technologies are, resource intensive and costly. Among the EOR technologies available to today; a new and cost-effective option is 'low-salinity' water Injection. Low-salinity water injection involves injecting fresh water into the oil-reservoir as fluid for a water flood. It has been observed that far greater yields of oil can be produced by low-salinity injection when compared to conventional water-flooding. The exact mechanism of low-salinity water injection is still not well understood. This paper aims to verify one proposed mechanism of low-salinity water injection i.e. the effect of swelling and non-swelling clays present within the reservoir with respect to the pH and the polarity of oil on the relative extraction of oil from reservoir samples. In light of the experiments conducted, it's apparent that the low-salinity water injection does indeed work better compared to the normal-salinity flood conducted throughout the experiment: increasing the oil recovery by zero.6 mg/g of oil per kaolinite with an equivalent adsorption ratio at a pH scale of 4. The results collected throughout the devised experiment summarily prove the existence of an underlying mechanism with a chemical route, due to the influence of pH scale and therefore the relative unaffected nature of bentonite with reference to the lLow-sSalinity chemical mechanism.

miscibility, that work on essentially completely effectiveness low-salinity water injection [16][17][18].different principles.Carbon dioxide injection is EOR is considered as one of the promising options practiced wide within the United States of America, and vital source for the further research to evaluate as Carbon dioxide reservoirs are extensive and the widely adopted mechanism of the action for lowtherefore the EOR methodology is compatible with salinity water injection.EOR is the struggle for the the rock oil system.Like most of the Oil fields within more recovery of crude oil from the oil wells and the Americas, the viscousness of rock oil could be a re se rv oi rs us in g th e ad va nc ed de ve lo pe d major concern [4][5][6].Vicious oil is far more durable technologies with costs in mid.Low salinity water to flow to the surface and so ends up in an occasional injection is one of those advanced developed recover.Thermal EOR strategies address this issue technologies [19][20][21][22][23]. by providing thermal energy to the reservoir so as to Objectives of this experimental investigation is to decrease the oil viscosity, and so rising the recovery.
prove that low-salinity water injection works only Chemical injection is an extremely broad field that when kaolinite is present within the formation rock improves the recovery by altering the fluid in s uff ici ent qua nti tie s, a nd t o lo ok i nto properties, or the rock-fluid interactions.the effectiveness of pH of formation crude during the primary driving factor to consider for new or low-salinity injection to make it a viable EOR obscure EOR technologies is the value of oil, and method.therefore the value of the EOR methodology itself.

Materials and Methods:
With spikes in the oil prices that were encountered Kaolinite samples were obtained from an off-site in the early 2010s, a new range of EOR technologies quarry in Tapah, a small town in Malaysia.were seen.From existing niche technologies, like Kaolinite exists as a white soft mineral that is soft to alcohol flooding to the technologies straight out of the bit and crumbles simply.Pure kaolinite is white; science fiction, such the pulse drive-used within the any impurities present would otherwise color it.Russian Federation.It is in fact possible to extract The kaolinite collected from the quarry in Tapah for the very last drop of oil from the crude oil reservoirs Low-Sal injection is tainted a light red, that within the world, however cost of doing so would be signifies the presence of iron (I) oxide as an phenomenally high.thus, deemed impossible by the impurity.The samples acquired had quartzite and cost-of oil/cost-of-EOR.Low price EOR strategies Flint impurities within the variety of little gravel are much more usable than sophisticated and sized particles.These Impurities were separated by expensive technologies [7][8][9][10].
hand before the rock was crushed.It ought to be Considering the EOR techniques presently being noted that the kaolin samples are of comparatively utilized, low salinity water injection could be a new prime quality, the slight cherry-red color is solely viable option.Though not currently practiced due to the presence of trace iron oxide impurities.

widely, it is an efficient technique. Studies of low
The kaolin rocks were at the start held in plastic bag before crushing.The rocks were then placed to salinity established the correlations of oil-extracted mortar and pestle within the work once initial to the low saline brine injected [11,12].The sorting.This sorting was to get rid of the quartzite mechanism of action for this comparatively new and different grit sized impurities from the soft clay EOR technique is however still stands to be chunks.once crushing the pulverized clay was determined at the laboratory level, before it's sieved employing a 0.5 mm sieve and hold on in a through implementation within the field [13][14][15].
very beaker that was coated to stop and Now days, the EOR is considered to a one of the contamination of the work or contrariwise.Samples dynamic fields in this area.Therefore, EOR always of bentonite clay were acquired from Schlumberger has been a subject of the fast developments in new MI Swaco lab.Bentonite is light brown clay which is technological options.However, most of these commonly used in drilling fluids as a viscosifier reported technologies do not compare to the cost-(Fig.1).

Preparation of Samples:
The kaolin sample was crushed to a fine powder then washed with distil water before being dried and crushed once more.The samples were separated into 200 g beakers.The bentonite was already in crushed and cleansed type.The oil samples were acquired so their acid variety was tested.The pH of the Oil was measured with a normally availably pH meter within the research lab.Before use, the list of crude oils was filtered to get rid of any solid particles.The properties of oil are Figure 1: Kaolin and bentonite in powder form.
tabulated in (Table 1).Brines were prepared by artificial means by get rid of particles if any (Fig. 2).The properties of dissolving salts into distilled water, and so filtered brine are tabulated in (Table 2).to get rid of any particles.All brines were filtered to methodology.Kaolinite powder, 100g, was added and stirred with 20ml formation brine for two hours before addition of organic oil or basic/acidic crude, and once more stirred and agitated for an additional twenty-four hrs.pH was adjusted with HCl or NaOH to stay the pH constant.Once settled, the samples were stirred at a high speed for twenty min (Fig. 3).

Experimental Procedure:
3).Adsorption of organic material onto kaolinite at room temperature was measured by a batch

Results and Discussions:
components of either an acidic or a basic nature must be present within the oil.Lastly, Kaolinite Regarding the experiments conducted, a number of must present within the rock.assumptions should be created so as to proceed, the Clays have an abundant surface area, and act as a subsequent parameters are therefore deemed to particle exchanger within the reservoir.All clays play an important role in low-salinity injection: have an ion exchange potential.Before any type of It can be assumed that the EOR impact of lowsalinity water injection is because of the adsorption injection into the reservoir an equilibrium of ions and desorption of oil onto the formation-clay exists.All polar elements within the formation oil surface.The initial composition of the formation are drawn to and therefore connected to the surface brine is assumed to be highly saline.Polar of the clay minerals.This includes the basic and the Oil Adsorbed (ml) After adding low salinity, the oil previously adsorbed was desorbed.The summary of desorption is tabulated in (Table 4).
The experiment was repeated for pH 4 with the following results (Table 5).water i.e. water with a far lower concentration of RCOOH + OH = RCOO + water ions than the initial formation water, the ionic From the experiments conducted the subsequent is equilibrium is disturbed.This disturbance within concluded: first off, it's the conformation that the oil the ionic equilibrium causes the immediate within the reservoir should be of a polar nature for desorption of calcium ions into the surrounding there to be any important increase within the water, since the encompassing water due to having extraction of oil.This is confirmed as nearly no oil is a very low concentration of the calcium ions.The absorbable on to the Karoline small-grained surface desorption of calcium ions causes the hydrogen ions if the oil is of a neutral nature, as it was discovered present within the water to adsorb to the surface of within the case of organic vegetable oil that is of a the clay-this cause the native pH to rise neutral nature.These experiments were continual considerably as there's currently an absence of H+ and consistent.The summary of the adsorption of Table 6.Summary of the adsorption of neutral oil.

Relative Adsorption:
injection once scaled up to the reservoir scale.The The results were more noticeable with exploitation average desorption capacity over pH of 4 is shown in of a polar oil.It had been apparent that kaolinite is (Fig. 5).extremely sensitive to the pH of the solution.Kaolinite was approximated to possess a mean adsorption ratio of 2.8 (mg/g) once polar oil was absorbable within the presence of a 4 pH acidic brine solution.The adsorption ratio goes down drastically because the pH approaches the neutral pH of 7 (Fig. 4).

Desorption of Oil:
Oil was desorbed once brine was added to the solution.Though there was no important distinction between the conventional formation brine addition, there was a rise in the oil desorbed when injecting low salinity water-important enough to prove the viability of low-salinity water

Figure 2 :
Figure 2: Preparation of Brine on a hot stirrer plate.

Figure 4 :
Figure 4: Adsorption behavior over variation in pH.

Table 1 :
Properties of Oil.
2 Type of Oil pH Viscosity (mm /sec) Density (g/cc)

Table 2 :
Properties of brine.

Table 3 .
Summary of adsorption.

Table 5 .
Adsorption-desorption results at pH 4. 2022 acidic elements of crude oil.It should to be noted ions.