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This report contains the results of simulated oilfield environment tests. These tests involved the exposure of C-ring specimens of duplex stainless steels to environments containing H₂S, CO₂ and brine at elevated temperatures.

The present study involved the evaluation of selected stainless and nickel base alloys in the following acidizing media: (1) 15 percent HCl, (2) 28 percent HCl, (3) 12 percent formic acid and (4) 13 percent HCl/2 percent HF. Tests were conducted both with H2S and with CO2 at 200 F and 400 F. Two different inhibitors were used in each acidizing media.

Samples of elastomeric materials were provided for evaluationof performance in high pressure gas environments containing CO₂,CH₄ and N₂. Of particular concern are theeffects of rapid decompression from test pressure andenvironmental degradation of the materials. The series of testsconducted in this investigation was developed to generateinformation that will aid in the selection of elastomericmaterials for wellhead service where high pressures, temperaturesand CO₂ concentrations are present.

Presented herein are the results of stress corrosion cracking (SCC) tests performed to evaluate the effect of silicide coatings on the SCC resistance of AISI 304 stainless steel in an elevated temperature chloride-continuing solution.

Presented herein are the results of the Task 2 Corrosion Resistant Alloy (CRA) Evaluation. These tests were conducted to determine the corrosion and stress corrosion cracking behavior of selected high alloy materials under conditions simulating those found in the Thamama gas.

The use of corrosion resistant alloy (CRA) tubulars for on injectionwell offers a method of providing (1) long term protection fromcorrosion and (2) maximum efficiency of flow. The use of thesematerials as downhole tubulars has only recently been attempted. Without extensive field experience on which to base materialsselection decisions, expected performance has been based on evaluationsconducted in the laboratory with simulated field environments. In these tests, the effects of corrosive species such as CO₂,H₂S, O₂, brine and acids are quantified. Performance in terms of pitting, crevice and general weight losscorrosion behavior and stress corrosion cracking behavior mustbe determined.

Samples of elastromeric materials were provided andevaluated to assess performance in a high pressure gas environmentcontaining CO₂ and CH₄. The study presented herein was conducted as an extension to work, described earlier. All test methods employed presently are similar to those described in depth in the previous report and will be only briefly covered herein.

Corrosion tests conducted in inhibited 60% LiBr indicate that liquid phase corrosion rates remain low even up to 350 F. However, vapor phase and liquid-vapor interface corrosion rates are such that carbon steel will require protection above 300 F. 70-30 cupro-nickel showed low corrosion rates with no pitting at all temperatures tested. Grade 2 titanium showed significant pitting at all temperatures tested. Grade 7 titanium showed significant pitting at 300 F and above. Fluoroshield, a fluorocarbon polymer coating, performed well in these tests and appears to be a viable method for protecting carbon steel in LiBr environments.

Presented herein is the review of material requirements a production well. This review includes evaluation of guidelines for wellhead and Christmas tree components which will be in contact with produced fluids under the following conditions: Partial Pressure CO2: 2.30 bar maximum; Partial Pressure H2S: 0.015 bar maximum; Water: 0-60 vol. Percent; Chlorides in Water: 2 wt. Percent; Reservoir Temperature: 94 C

Flow loop tests were conducted to evaluated the erosion-corrosion resistance of cupro-nickel heat exchanger tubes. 95-5 and CA 122 tubes were subjected to 10, 15 and 22.5 ft/sec flow rates in 45 F refreshed tap water for three, six and nine month periods, then returned to a separate contractor for evaluation.

Pitting has been observed on a string of 316L injection tubing that is used to inject waste water. The pitting is not severe, but is sufficiently rapid to eventually cause perforation of the pipe and subsequent replacement.The cause of pitting is thought to be associated with one or more fluids that are caused in conjunction with stimulation practices. Some five different chemical formulations (including the waste solution) are suspect. Electrochemical tests were performed to ascertain the cause of pitting and to recommend possible solutions.

A Waste Disposal Company is involved with a project in which wastesludge is oxidized to ash using O₂. Inlet conditionsto the reactor involve sludge having a velocity (linear, in piping)of approximately 10 fps. Outlet conditions are similar with theexception that the sludge has been transformed to inorganic materials (ash) plus CO₂ and water. The temperature of the reactor is in the range of 700-800 F. Products and reactants vary in temperature depending on their proximity to the reactor.

Qualifications test were conducted on Inconel 825 according to NACE and ASTM standards. Three bars representing separate heat and bar diameters were used for the tests. The material dimensions and corresponding heat and identification numbers are shown.