Dependence of the Equivalent Circulation Density of Formate Drilling Fluids on the Molecular Mass of the Polymer Reagent

Abstract

Construction of offshore gas wells is characterized by increased requirements for both the technological process in general and the technological parameters of drilling fluids in particular. Parameters and properties of the used drilling muds must meet a large number of requirements. The main one is the preservation of the permeability of the reservoirs, in addition to the environmental and technological concerns. At the same time, pressures in the productive formation at offshore fields are often high; the anomaly coefficient is 1.2 and higher. The use of barite in such conditions can lead to contamination of the formation and a decrease in future well flow rates. In this regard, the development and study of the compositions for weighted drilling muds is necessary and relevant. The paper presents investigations on the development of such a composition based on salts of formic acid (formates) and evaluates the effect of the molecular weight of the polymer reagent (partially hydrolyzed polyacrylamide) on the equivalent circulation density of the drilling fluid. The result of the work is a formate-based high-density drilling mud with no barite added. Application of such a mud will preserve the permeability of the productive formation.

Application of High-Density Brines in Drilling and Completion Fluids: Current Insights and Future Perspectives

“…The outcomes proved that formate-based barite-free drilling mud demonstrated a better environmental profile as compared to other commonly used brine mud systems . The same research group also studied the effect of equivalent circulation density of formate drilling fluids on the molecular mass of the polymer reagent …”

“…135 The same research group also studied the effect of equivalent circulation density of formate drilling fluids on the molecular mass of the polymer reagent. 136 The application of formate-based brine improves not only the productivity of the oil well but also the stability of the reservoir enormously. However, the formate-based brine never performed well in the return permeability tests; therefore, acid treatment of the core plug was done.…”

Reviewing the advancements in offshore drilling technologies in the USA and their global impact

“…In terms of environmental stewardship and reduction of the industry's footprint, the USA's offshore drilling advancements have the potential to impact the natural environment. The construction of offshore gas wells is characterized by increased requirements for both the technological process in general and the technological parameters of drilling fluids in particular (Leusheva et al, 2021). Moreover, the increased complexity of Arctic offshore drilling waste handling facilities, coupled with stringent regulatory requirements such as zero "hazardous" discharge, calls for rigorous risk management practices (Ayele et al, 2016).…”

Application of Hydrogels and Hydrocarbon-Based Gels in Oil Production Processes and Well Drilling

“… Uncontrolled inflow of formation fluid into the well [ 220 ]. Regulation of the density of the drilling flushing fluid [ 215 , 221 , 222 ]. Swelling of clay rocks [ 223 , 224 ].…”