... Abstract Recent times have seen an advancement in the area of carbonate acidizing, moving forward from single-phase to two-phase analyses, in an effort to account for the presence of the oil-phase during stimulation treatments. Yet, a lack of a complete capability to understand this complex...

... Abstract The success of carbonate acidizing depends on the selection of proper fluid recipes, reservoir formation parameters, job design, and execution. Analysis of flowback spent acid will improve the acidizing process in future treatments, enhance the designed recipes and treatment design...

... amine by reacting it with organic and inorganic acids such HCl, acetic acid, and formic acid; as well as alkylating agents, including chloromethane, benzyl chloride, diethyl sulfate, and paraformaldehyde. Certain cationic polymers have also proven useful as clay stabilizers. These much larger molecules...

... Abstract Carbonate reservoir matrix acidizing is commonly conducted with HCl. In these treatments, HCl acid is used to create conductive channels (wormholes) to enhance well productivity/injectivity. However, its use has been limited due to associated rapid tubulars corrosion and formation face...

... Abstract Polylactic Acid (PLA) is increasingly used in the oil industry and specifically for diversion in matrix acidizing as evidenced by a number of field cases recently published. The solid polyester is particularly attractive due to its ability to degrade in the presence of water and heat...

... Abstract Matrix acidizing is used for permeability and productivity enhancement purposes in oil and gas wells. Hydrochloric acid has been always a first choice due to so many advantages that it can offer. However, HCl in high pressure/high-temperature (HP/HT) wells is a concern because of its...

... Abstract The optimum design of matrix acidizing treatments in carbonate reservoirs requires accurate modeling of wormhole propagation. While there are several wormhole correlation models available, most are developed based on small core scale experiments, and result in significant deviation...

... Abstract Matrix acidizing has long been used for permeability and productivity enhancement purposes in oil and gas wells. In sandstone reservoirs, a preflush is needed to dissolve carbonate minerals so that HF is not consumed in the main step on carbonate minerals. The preflush step also...

... Abstract Successful matrix acidizing of carbonate reservoirs depends on the selection of optimal stimulation fluids. Because of the rapid reaction rate and corrosive nature of HCl in downhole conditions, other alternatives are much in demand. Organic acids, particularly methanesulfonic acid...

... Abstract Viscoelastic surfactant (VES)-based acid systems are used in acid-diversion applications. However, high- temperature, interaction of the VES and Fe(III) (as a contaminant), addition of alcohol-based additives, and chelating agents all interfere with the apparent viscosity of the VES...

... Several field studies have been reported for application of emulsified acid (Al-Anazi et al. 1998 ; Nasr-El-Din et al. 2000 ; Madyanova et al. 2012 ). Application of matrix acid treatments in heterogeneous formations or large permeability contrast formations requires a diverting agent stage...

... An alternative approach to circumvent undesired HCl reactions near the wellbore involves particles encapsulated with acid. By encapsulating HCl within a hardened shell, the acid is isolated from the surrounding environment for an engineered timeframe of release, thereby postponing reactions...

... Abstract Acid stimulation is one of the production enhancement methodologies applicable in both development and exploration fields. Sandstone acidizing requires a sophisticated and well-studied approach to avoid formation damage caused by acid precipitation. Although the industry has made...

... was acidified using concentrated HCl at a volume to make a 15% solution and at a rate of addition to help ensure no excessive heating during addition. The solid diverting agent was added to the gelled acid to make a 0.22, 0.44, 0.66, or 0.88 M suspension. Following preparation, the fluid was added to an oven...

... carbonate precipitates without causing corrosion. Rabie and Nasr-El-Din (2015) investigated sodium gluconate as an efficient and environmentally iron controlling agent in matrix acidizing treatments. The results of this study showed that the presence of wt% sodium gluconate with the injected HCl...

...Materials Abstract Methanesulfonic acid (MSA) has been proven as a scale remover and, more recently, as a stand-alone stimulation fluid in carbonate acidizing. MSA is a strong alkyl sulfonic acid having a pK value of -1.9, and it dissolves carbonate and oxides with its calcium water-soluble...

...Materials Regular strength and half strength sandstone acids are used as receveid from a service company, which contain a corrosion inhibitor, a clay stabilizer, and an iron control agent, Table 1 . The corrosion inhibitor is a blend of quaternary salts, alcohols, formamide, and ethoxylated...

... these aggregations of asphaltenes become large enough, precipitation can occur. In crude oil, natural resins peptize the asphaltenes, but upon exposure to acid these resins are often not enough to prevent flocculation. This is often because acid entering the oil phase protonates basic groups on the asphaltene...

... Organic acids cannot be used at high concentrations because of the precipitation of calcium salts. Thus, the concentrations of acetic and formic acids used are less than 13 and 9 wt%, respectively. This is because the reaction products (e.g. calcium formate) can precipitate at higher acid...

...Experimental Studies Materials Abstract During matrix acidizing, successful iron control can be critical to the success of the treatment. Iron (III) precipitation occurs when acids are spent and the pH rises above 1, which can cause severe formation damage. Chelating agents are used...