TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractActual worldwide oil production averages some 75 million barrels per day and, while estimates vary, this is associated with the production of 300 -400 million barrels of water per day. These values of approximately 5 -6 barrels of water for every barrel of oil are quite conservative. In some areas around the world, fields remain on production when the ratio is as high as 50 to 1.Water production causes several problems to oil wells such as scaling, fines migration or sandface failure, corrosion of tubular, and kills wells by hydrostatic loading, amongst other things. Thus, while water production is an inevitable consequence of oil production, it is usually desirable to defer its onset, or its rise, for as long as possible.Numerous strategies, both mechanical and chemical, have been employed over the years in attempts to achieve this. Simple shut-off techniques using cement, mechanical plugs and cross-linked gels have been widely used. Exotic materials such as DPR (disproportionate permeability reducers) and the new generation of relative permeability modifiers (RPM) have been applied in matrix treatments with varying degrees of success. Most recently, Conformance Fracturing operations have increased substantially in mature fields as the synergistic effect obtained by adding a RPM to a fracturing fluid have produced increased oil production with reduced water cut in one step, consequently eliminating the cost of additional water shut off treatment later on.This paper is an evaluation of various RPM materials commonly used on Conformance Fracturing treatments performed in the northeast of Brazil and other South American countries, rather than the usual laboratory testing methods and theoretical estimations. The paper also describes the technical design and operational methodology to treat single zone to laminated reservoirs with different mobility ratios. We believe conformance fracture techniques could significantly impact the development strategies of many fields worldwide.

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fax 01-972-952-9435. AbstractGravel packs completions are widely used today on unconsolidated formations worldwide, as to provide sand control, and, as such, behaves as a filter. A filter is subjected to be plugged by fines, (heavy) hydrocarbons, scale depositions, among others, which may result in a considerable drop of production, or even total lack of. The synergism of coiled tubing rotating, cyclical jetting tools, and adequate acid systems has demonstrated great results in Northeast of Brazil. The cyclical jetting tool acts to disaggregate plugging particles from the gravel, and the acid acts to chemically dissolve acid soluble plugging materials. The acid system utilized is quite unique and simple. The method consists of pressure cyclically jet solvent and a small amount of a specially designed acid system, to clean up the gravel pack. No acidic flushes are used ahead or after the acid system, because the acid system is a high pH one (2 -3), and uses an organophosphonic acid to control the dissolution of carbonates, and, therefore, controls the precipitation of insoluble fluorides. This way, release of calcium ions is less likely to occur. The main acid system is hydrofluoric (HF) based, generating HF on a controlled fashion, using much less hydrochloric acid (HCl) when compared to regular HF acid systems. This paper describes three gravel packed wells treated with this single step acid system. These wells were very similar, and used the same acid recipe However, the first well was treated with a rotating pressure cycle jetting tool, and the remaining two wells used a different pulsation tool. All wells showed production increase, but the first well yielded much better results compared to the last two. Results from these three treatments will be presented and compared as towards the effectiveness of coiled tubing tools deployed.