Corrosion is the natural and continuous degradation of materials caused by either chemical, mechanical, or electrochemical reactions. Corrosion inhibitors may be added to the completion fluids to address corrosion problems efficiently. It is critical to add corrosion inhibitors in completion fluids, specifically under high-temperature conditions, since the corrosion rate is higher when the temperature is high. This corrosion process limits the life of the drill tools or the oil and gas well and causes formation damage. This research studied corrosion and corrosion inhibition treatments for five completion fluids, namely potassium chloride, sodium chloride, sodium bromide, calcium chloride, and calcium bromide. Phosphate and sulfite-based corrosion inhibitors were individually added to the completion fluids, and their corrosion properties were studied to tackle the corrosion issue. In addition, a mixture of phosphate-based and sulfite-based corrosion inhibitors in completion fluids was studied. Additionally, the experimental results recommend using divalent brines as they were identified as a better medium for lowering corrosion rate and conditions than the monovalent brines. A novel aspect of this study is that the materials leveraged for conducting experiments are also used in actual petroleum production field operations. The experiments demonstrate that the corrosion rate can be efficiently controlled at high temperatures in deeper wells.

Well integrity is defined as technical, operational, and organizational solutions specifically aimed at the reduction of the risk of formation fluids release throughout a well's life cycle. Cement integrity is one of the main aspects that comprises well integrity. Cement integrity must be ensured throughout a well's life cycle as well as after abandonment. If the cement was to lose its integrity, the consequences for the personnel, the equipment, and the environment could be severe. Cement failures might lead to leakages that can seep through the cement pathways; sealant materials are used to plug these pathways. The actual and real-time disputes are mainly dependent on the technical approaches currently available to limit the main causes of well integrity deficiency. These include cementing jobs, substantial design based on downhole conditions, material selection criticality, well construction performance, and technological resources. Additionally, in this specific context, well integrity also refers to the control of the flow inside the wellbore (between different horizons) and the flow from the well (especially in the annulus behind the casing). The worst-case scenario would be the loss of wellbore integrity, and it would be identified as the collapse of the well caused by failure of the construction material. The focal point of the research presented in this paper is the cement quality and its role in developing the most vigorous well casing possible. The focus was centered around resin additives such as microbond, latex, and crystal seal. Microbond is a white mineral cement-based liquid with exceptional performances when combined with cement. Latex is composed of rubber particles dispersed in water, usually found in white liquid form. Crystal seal is a yellow colloidal material highly regarded for sealing properties when mixed with concrete mixtures. These additives were individually incorporated into cement-based samples, in varying concentrations, for testing the changes in properties suitable for well integrity considerations. Highly specialized and sophisticated cement testing apparatuses, such as the ultrasonic cement analyzer (UCA), static gel Strength machine (SGSM), and curing chamber, have been used to perform qualitative and quantitative property gradient tests. Based on the performed experimental tests results, the optimal additive resin for a class G cement slurry is the microbond additive at a concentration of 7.5%. The results highlighted its ability to enhance the cement compressive strength by 52%. Additionally, the transit time showed a 26–42% range decrease in the travel period, indicating that the cement was stronger under increased pressure and temperature. This can clear up the permeable section of the well wherein the cement-resin slurry could efficiently close off wellbore intersecting faults and, therefore, prevent possible connections between the wellbore and water zones in the subsurface. As a result, microbond, latex, and crystal seal, respectively, show the effect of varying controlled conditions as functions of the increase in concentration, curing time, and temperature to its comparable properties such as breakload, compressive strength, and ultimate break force. This study can further support future analysis in improving the reliability of petroleum well constructions.

Effective stimulation of thick, layered carbonate reservoirs is required to reach production targets for present and future demand. It is common that the completed intervals intersect several layered reservoirs, commingle multiple zones, and extend hundreds to more than a thousand feet in length. Even with the best petrophysical measurement and interpretation available in the industry, the key formation parameters considered in acid stimulation are still clouded by uncertainty. Several matrix acidizing techniques have been applied to stimulate these types of reservoirs based on the knowledge of petrophysical data. This paper strives to outline some of the key pitfalls that can occur due to the uncertainty in this data. Using reservoir simulations, the long term adverse impact of these pitfalls on both production and overall recovery can be shown. A new acid diverter, based on degradable fiber and visco-elastic surfactant technologies, has been applied, along with a placement model, to optimize treatment design and to maximize diversion in heterogeneous carbonate reservoirs. The system is robust, diverting from high permeability streaks, fissures and natural fractures with very little diverting effect from the low permeability zones, and therefore generates a more uniform stimulation than conventional fluid systems. This approach has been used to optimize various stimulation campaigns on carbonate fields throughout the Middle East. Maximizing treatment fluid coverage across the entire intervals can be achieved across thick, even naturally fractured, carbonate intervals using degradable fiber technology within a visco-elastic surfactant fluid. The diversion technique does not overly rely on certainty in petrophysical data, such as permeability and porosity, and can be successful in a variety of potential scenarios.