Formation Damage Abatement: A Quarter-Century Perspective

Abstract

Summary Petroleum well production impairment has long been associated with formation damage. Concepts such as the skin effect and its various manifestations have been introduced to account for the effects of damage. The origins of damage and the types of damage also have been the subjects of intense scrutiny. Abatement has included preventive measures such as the use of nondamaging fluids, presumably more benign processes, and improved drilling and well construction procedures and techniques. Once in place, the removal of damage has spawned an entire industry, that of matrix stimulation. This involves the use of appropriate remediation fluids, complete with the understanding of the often contrasting interaction among these fluids, the fluids and the damage, and, very importantly, the side effects that can damage the well more than its prestimulation state. Again, appropriate hardware was necessary. Owing to the fact that damage removal is often either incomplete or unsuccessful, methods of bypassing the damage, such as high-permeability fracturing, have been developed. Finally, brute force approaches are common, including the drilling of more vertical and/or horizontal wells regardless of the damage in order to get enough production. This paper is a critical review of both the evolution of the technologies and the thought processes that have permeated the industry over the past quarter century. Particular emphasis is given to the resolution of controversial subjects and their impact on the field. These include issues such as matrix stimulation vs. fracturing, sand production control vs. sand deconsolidation management, underbalance vs. extreme overbalance, and perforating and drilling fluids and practices. Introduction A routine procedure of early-day operators to keep many wells in production was "clean out, shoot, clean out again." Therefore, the idea of formation damage abatement has not been an esoteric phenomenon to the industry. Engineers have long yearned to prevent, diagnose, and remediate formation damage. The disagreement has been over how to accomplish it. These concerns continue to permeate the literature and various technical gatherings. Finally, SPE approved the formation of a formal symposium. The first Symposium on Formation Damage Control was held in 1974 in New Orleans. This was followed by symposia in Houston (1976), Lafayette, Louisiana (1978), and Bakersfield, California (1980). The location of the symposium alternated between Lafayette and Bakersfield until 1990, when Lafayette became the sole host of the symposium (Table 1). In 1992, the SPE Board approved the international designation for the symposium. The 2000 Symposium was the silver anniversary of the event. During its 25 years, the symposium has grown from a regional event to today's major international symposium, attracting more than 800 participants from more than 30 countries representing 6 continents. The success of the symposium prompted the initiation of the sister conference during the off years in The Hague, The Netherlands, beginning in 1995. The International Symposium and Exhibition on Formation Damage Control (ISEFDC) has contributed nearly 600 technical papers to the literature (Tables 1 and 2). We have selected what we consider some of the most important topics in damage, damage characterization, prevention, and abatement. While this paper by no means exhausts the subject, it is a reasonably comprehensive description of the evolution of both the technology and, especially, the thought process over the last 25 years. Other meetings and journals may have additional relevant material. Wherever absolutely necessary, we have included important references from these sources. However, because of our intimate and lengthy involvement with the organization and nurturing of the International Symposium on Formation Damage Control, particular emphasis was given to the works that appeared at these events. This is not limiting, because the Symposium has evolved over time into the premier international meeting on the subject. Aspects of Drilling Damage A successful completion must begin with the drilling of the well. All decisions thereafter concerning the well should be made only after careful consideration of their effect upon the ultimate flow performance of the well. Industry practitioners have long recognized that the various facets of drilling operations can induce production impairment. Unfortunately, this was not apparently a sufficient incentive for drilling personnel to become more actively involved in the formation damage debate. The only exception to this observation is perhaps in the drilling fluids industry, in which sales motivations could have played a major role in the development of new and improved products. To its credit, the industry has made great strides to introduce nondamaging fluids.1–6 Recently, drill-in fluids that minimize particle invasion have sparked many studies for designing muds to reduce rock impairment. Regarding drill-in fluids, one should be aware of the current technological weaknesses, such as long-term scale inhibition for high density brines, iron solubility control, and wellbore preparation and cleaning methods. Washouts in the producing zones have been found to greatly reduce the chances of obtaining a satisfactory cementation. Furthermore, in such cases, mud filtrate reduces reservoir permeability by dispersed clays. Therefore, slower drilling in the objective interval must be accepted, even though it may not be the cheapest way. The problem of formation damage and annular blowouts or pressures owing to migration through cemented annulus was recognized in the mid-1960s and resulted in new cementing procedures. 7,8 Cementing (primary and remedial) continues to be one of the toughest (if not the toughest) challenges in drilling, completing, and producing a well. The industry emphasis seems to have been in introducing better cements and spacer fluids rather than in more effective placement. Casing deformation in, or adjacent to, the producing intervals has been encountered in one of four wells entered for recompletion or repairs. Initially, it was thought that the casing was collapsed. Using instruments developed for this purpose, such as the kinkmeter and casing caliper, it was determined that the deformation was caused by buckling. Pressure decline, causing compaction and axial loads, and sand production, causing loss of lateral support, were recognized as the reason for buckling. For minor casing damage, the use of undersized, inflatable packers or squeeze tools, flexible wire-wrapped screens, and knuckle joints were found useful. For more severe damage, milling operations have been recommended. 9 Other studies described the mechanisms of drilling and production-induced damage.10,11

Hydraulic Fracturing Characteristics and Stimulation Optimization of Tuffaceous Sandstone Reservoir in San Jorge Basin, Argentina

“…Fracturing calibration test analysis also confirmed this point. The test in this work area showed that about 66% of the wells belong to the situation of excessive fracture propagation in height [27], which was basically consistent with the monitoring results in the adjacent area [28,29]. During hydraulic fracturing, the fracture mainly propagated longitudinally.…”

Application of In-House Prepared Nanoparticles as Filtration Control Additive to Reduce Formation Damage

“…Formation damage is an aspect considered during drilling to ensure an effective well completion (Ghalambor and Economides, 2002). It impacts on well productivity and injectivity (Bryne and Rojas, 2013) and needs to be mitigated for the conduction of a successful exploitation project.…”

Application of a new family of organosilicon quadripolymer as a fluid loss additive for drilling fluid at high temperature

“…When drilling in deep wells for oil, gas, and geothermal energy resources in deep environments, high temperatures are usually encountered, which adversely affect the performance of drilling fluids. In particular, bentonite gels develop that result in loss of filtration control causing formation damage, which can be detrimental not only to the drilling activity but also to later production and cause deterioration of the rheological properties of drilling fluids 6–11. At extreme temperatures, special formulations and systems must be used 12–14.…”