Formation water salinity

Salinity reversals or decrease of the formation brine salinity with depth are generally associated with overpressured formations. The mud salinity or chloride content reflects the formation water salinity if there is a close control over the mud properties and analyses. 

Formation water salinity and divalents are critical to chemical EOR processes for both surfactants and polymers. Although chemical suppliers claim their products can be tolerant to high salinity, most of the chemical EOR processes have been applied in low-salinity reservoirs. For most of the Chinese EOR projects, the formation water salinity is below 10,000 ppm, and fresh water is injected. The criterion Al-Bahar et al. (2004) discussed is 50,000 ppm salinity and 1000 ppm hardness. This 1000 ppm hardness is probably too high or needs... 

PPGs are strength- and size-controlled ( am-cm), environment-friendly, and stable up to 110°C in the presence of almost aU reservoir minerals and formation water salinities. 

Seawater with a TDS of 32,423 mg/L was injected for 8 years. The history of water injection made the salinity of produced water higher than the formation water salinity, especially the divalent. The water used in the polymer solution was initially Guantao formation water followed by a mixture of Guantao... 

Oil viscosity shonld be less than 50 to 100 cP. However, cnrrently alkaline-surfactant injection into very high viscous oils has attracted more and more interest (see Chapter 12 on alkaline-surfactant flooding). Formation water salinity should be less than 20%, and the divalents in the injection water shonld be less than 0.4%. 

After ASPF flooding, the chloride ion concentration of the effluent fluid at all the producers increased significantly, as shown in Figure 13.49. We can see that the volumetric sweep efficiency was increased because the formation water salinity was much higher. 

Nikiel, a. M. Manor, J. S. 1999. Spatial variations in formation water salinities. South Pelto and South Timbalier areas, eastern Louisiana continental shelf Transactions of the Gulf Coast Association of Geological Societies, 49, 396-403. 

Data gathering in the water column should not be overlooked at the appraisal stage of the field life. Assessing the size and flow properties of the aquifer are essential in predicting the pressure support which may be provided. Sampling of the formation water is necessary to assess the salinity of the water for use in the determination of hydrocarbon saturations. 

Formation water density is a function of its salinity (which ranges from 0 to 300,000 ppm), amount of dissolved gas, and the reservoir temperature and pressure. As pressure increases, so does water density, though the compressibility is small... 

If the technical regulations are adhered to for constructional steels in neutral waters, there are no conditions for H-induced corrosion. On the other hand, hardened and high-strength materials with hardnesses above HV 350 are very susceptible [60,82,92], since anodic polarization encourages crack formation in saline media and anodic pitting occurs with acid products of hydrolysis [93]. 

I Ualloy ferrous materials Neutral waters, saline and soil solutions (25°C) <-0.53 <-0.85 Protection against weight loss corrosion Fig. 2-9 [29-34] (with film formation is more positive)... 

The mud contamination with chlorides results from salt intrusion. Salt can enter and contaminate the mud system when salt formations are drilled and when saline formation water enters the wellbore. 

There have been numerous reports of possible allergic reactions to mercury and mercury salts and to the mercury, silver and copper in dental amalgam as well as to amalgam corrosion products Studies of the release of mercury by amalgams into distilled water, saline and artificial saliva tend to be conflicting and contradictory but, overall, the data indicate that mercury release drops with time due to film formation and is less than the acceptable daily intake for mercury in food . Further, while metallic mercury can sensitise, sensitisation of patients to mercury by dental amalgam appears to be a rare occurrence. Nevertheless, there is a growing trend to develop polymer-based posterior restorative materials in order to eliminate the use of mercury in dentistry. 

It is generally more saline than seawater. Most North Sea formation waters have salinities two to three times that of seawater. 

R. F. Scheuerman and B. M. Bergersen. Injection water salinity, formation pretreatment, and well operations fluid selection guidelines. In Proceedings Volume, pages 33-49. SPE Oilfield Chem Int Symp (Houston, TX, 2/8-2/10), 1989. 

Manheim FX, Pauli, CK (1981) Patterns of ground water salinity changes in a deep continental-oceanic transect off the southeastern Atlantic coast of the U.S.A. J Hydrol 54 95-105 Martin P, Akber RA (1999) Radium isotopes as indicators of adsorption-desorption interactions and barite formation in groundwater. J Environ Radioact 46 271-286 McCarthy J, Shevenell L (1998) Obtaining representative ground water samples in a fractured and karstic formation. Ground Water 36 251-260... 

Kraemer T, Reid D (1984) The occurrence and behavior of radium in saline formation water of the US gulf coast region. Isot Geosci 2 153-174... 

Scale inhibitors are used to prevent the formation of insoluble calcium salts when the drilling fluid contacts formation minerals and saline formation waters. Commonly used scale inhibitors include sodium hydroxide, sodium carbonate, sodium bicarbonate, polyacrylates, polyphosphates, and phosphonates. 

Earlier corrosion inhibitors limited the maximum strength of the acid to 15% by weight. Improved corrosion inhibitors (see below) have made the use of higher acid concentrations, such as 28% HCl more common. More dilute solutions may initially be injected in sandstone acidizing to reduce the formation of insoluble sodium and potassium fluorosilicates by displacing saline formation water before injection of hydrochloric acid. 

A series of processes will control the behaviour of C02 in saline aquifer formations. First, the C02 will displace the formation water (brine) originally in place and will lead to a local increase in pore fluid pressure (van der Meer, 1992). The injected C02 will not be distributed evenly, but will finger out, owing to the lower density than the pore waters and the heterogeneities of the aquifer. Doughty et al. (2001) point out that the shape of the C02 plume in the aquifer will be highly site- and case-specific. Carbon dioxide will rise to the top of the aquifer and migrate at the bottom of the... 

Formation waters are saline with salt contents ranging from ocean water to very dense Ca-Na-Cl brines. Their origin and evolution are still controversial, because the processes involved in the development of saline formation waters are complicated by the extensive changes that have taken place in the brines after sediment deposition. 

Although formation waters show a wide range in isotopic composition, waters within a sedimentary basin are usually isotopically distinct. As is the case with surface meteoric waters, there is a general decrease in isotopic composition from low to high latitude settings (Fig. 3.20). Displacements of 5D and 8 0-values from the Meteoric Water Line (MWL) are very often correlated with salinity the most depleted waters in D and O are usually the least saline, fluids most distant from the MWL tend to be the most saline. 

Knauth LP, Beeunas MA (1986) Isotope geochemistry of fluid inclusions in Permian hahte with implications for the isotopic history of ocean water and the origin of saline formation waters. Geochim Cosmochim Acta 50 419 33... 

A wide variety of zeolites are known to form in saline lakes where the species present is dependent upon the chemistry of the solutions. Rapid zeolite formation is aided by the existence of the volcanic glass and high water salinities. Potassium feldspar occurs with the common alkali zeolites (Hay and Moiola, 1963 Hay, 1964 Hay, 1966 Sheppard and Gude, 1969, 1971), however, albite is not evident as a diagenetic mineral in saline lakes. 

Salt water is present in the crude in the form of emulsion. When the produced formation water is highly saline as is the case in Kuwait, then straight dehydration is not the solution and the crude is to be desalted as well. 

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