Advances In Formation Damage Assessment And Control Strategies

Abstract

dwindle and exploration/development costs escalate particularly in frontier regions, the need for effective prevention and/or treatment of formation damage to maximize well productivity, has become apparent to prudent operators. This paper discusses wmomic implications, reviews various origins and forms, and provides method for recognition of formation damage. Geological and enoneering tests for Proper assessment of the problem, and optimization schemes for effrctive solution are also describe. BACKGROUND Formation damage is a condition which occurs when barriers to flow develop in the near-wellbore region to give rise to a lower than expected production rate from or injection rate into a hydrocarbon bearing reservoir rock. This problem has been recognized for several decades as a major contributor to anomalous production and/or abnormal decline in productivity or injectivity in most hydrocarbon reservoirs. Many potential pay zones have been misdiagonized as nonproductive, and payout on investment has been delayed because of formation damage. Understanding formation damage requires a multidisciplinary approach that involves such diverse specialty fields as inorganic/organic chemistry, physical chemistry, colloid and interfacial sciences, chemical kinetics, mineralogy, diagenesis and 65-1 fluid transport through porous media. Unfortunately, the primary interest of the various field groups involved in reservoir dermition and exploitation often seem to be in conflict. For instance, the driller is typically interested in reaching the targeted depth quickly( increased ROP), and safely (overbalance pressure condition), while maintaining a gauged hole. Avoidance of formation damage then appears to be of secondary concern.However, if a project team is formed at the outset to include drillers, mud engineers, geologists, production and reservoir engineers, then proper objectives of a safe drilling program can be set to protect the formation and to casure that the reservoir will be exploited to its maximum productive capacity to generate a maximum return on investment. Once formation damage has occurred, proper assessment and treatment WW require the cooperative effons of geologists and enpneers both in the field and in the laboratory. This synergistic approach is necessary to develop effcclive solutions to this expensive problem. Better understanding of the mechanism of formation damage is required in ordcr to develop effective preventive and mitigative procedures. With recent advances in technology, laboratory geological and engineering measurements can provide the many insights into the mechanism, prevention and cffcctive treatment of formation damage.

Drilling Fluid Technology: Performances and Environmental Considerations

“…Regarding the reservoir heterogeneity with wide mineralogical composition, rock-fluid interaction affects permeability and porosity seriously. Amaefule et al (1988) pointed out that five primary factors affect the mineralogical sensitivity of sedimentary formations: mineralogy and chemical composition, mineral abundance, mineral size, mineral morphology and mineral location. Mungan (1989) states that clay damage depends on the type and amount of exchangeable cations, such as K + , Na + , Ca ++ and the layered structure existing in the clay minerals.…”

“…Biological activity. Some fields present several other formation damages due to salt, scales, or asphaltene deposits and/or clays and fines migration, arising from different sources, such as work-over and snubbing operations, perforations, cement filtrate invasion, reservoir pressure depletion and other pseudo-skin mechanisms, such as turbulence in production, partial penetration, completion problems... Mineralogy and chemical composition, as well as the mineral by itself (size, morphology, abundance, and location), are considered as the primary factors affecting the mineralogical sensitivity of sedimentary formations (Amaefule et al, 1988). Moreover, Mungan (1989) stated that clay damage depends on the type and amount of their exchangeable cations.…”

Formation Damage Removal Through Acidizing of an Oil Well After Drilling and Completion

“…This situation is undesirable because it has a negative impact on the well and it will reduce the production capacity of the well. For instance, Amaelule et al (1988) stated that "Formation damage is an expensive headache to the oil and gas industries." However, any destroyed section inside the formation is due to the restriction to the flow of the hydrocarbons during the production process in a well.…”

“…This is because the invaded zone by drilling fluids that have bacterial agents will touch formation. Also, this will affect permeability and would have a negative impact on the well productivity and will also reduce the well performance (Amaelule et al, 1988). d. As it is known during the drilling operation of a well, there will be falling of drilling solids while drilling a hole and/or from the solids that was added to the drilling mud.…”

Experimental study of petrophysical properties of a tight formation by considering the clay minerals and flow sensitivities

“…Hower (1974) studied the distribution of clay minerals in the United States Gulf Coast and pointed out that the formation damage degree depended on the contents, types of clay mineral and their position in the rock. Krueger (1986), Amaerule, Kersey, Norman, and Shannon. (1988), Porter (1989) and Reed (1989) comprehensively reviewed the research of formation damage, which reflected the achievements of the 80s.…”