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The toxic properties of naturally weathered Exxon Valdez crude oil (WEVC) were assessed in a battery of acute and subchronic toxicity tests using mallards, Anas platyrhynchos, and European ferrets, Mustela putorius. Adult mallard acute oral toxicity study results indicated no mortalities or signs of toxicity, i.e., no‐observed‐adverse‐effect level (NOAEL) and median lethal dose (LD50) > 5,000 mg/kg. Acute oral feeding and food avoidance tests with ducklings also indicated no toxicity (NOAEL and LC50 > 50,000 mg/kg diet) with no evidence of food avoidance (FAC50 > 20,000 mg/kg diet). No mortalities or toxic signs were noted in a 14‐d feeding study with adult birds at dietary concentrations up to 100,000 mg WEVC/kg diet. Among clinical and physiological end points evaluated, the only significant difference noted was an increase in liver:body weight ratios in the 100,000‐mg WEVC/kg diet dose group. No differences in clinical chemistry or hematological parameters were noted, and there were no consistent differences in histological evaluations of organ tissues. Daily oral doses of up to 5,000 mg/kg of WEVC over 5 d resulted in minimal effects on ferrets. Increased serum albumin concentrations were observed in the 5,000‐mg/kg dose group females and decreased spleen weights were noted in females of all WEVC treatment groups. No other significant observations were noted.

Hydrogen sulfide (H2S) can be present in produced water discharged from production platforms along the Southern California Outer Continental Shelf (OCS). An assessment of the toxicity of H2S to marine organisms was conducted to determine if adverse effects could occur due to California OCS produced water discharges. Hydrogen sulfide toxicity is attributable to the undissociated H2S, which comprises approximately 3 - 8% of the total discharged sulfide in seawater. The dissociation of H2S is a function of temperature, pH, and salinity. H2S is not persistent in seawater and rapidly degrades by reacting with oxygen to form nontoxic thiosulfates. The oxidation half-life of H2S in seawater is reported to be between 0.4 to 3 hours. Data in the scientific literature indicate that marine species are less sensitive to H2S than fresh water species. Lethal effects to marine species have been reported to occur at concentrations as low as 20μg undissociated H2S/L in 96-hour laboratory exposures. No observable effect concentrations based on results from chronic toxicity bioassays that assess growth and developmental effects have been reported as low as 4 μg undissociated H2S/L. Produced water data from three production platforms were analyzed to determine the potential impact of H2S on marine life passing through the effluent plume or residing outside of the mixing zone. Calculations of the undissociated H2S at the edge of the mixing zone, taking into account natural oxidation of H2S to nontoxic thiosulfate, and comparing those concentrations with conservative chronic toxicity values, demonstrate that H2S in California OCS produced water discharges should not present a hazard to marine aquatic life.

Chevron Oil Field Research Company has developed computer programs for troubleshooting rod pumping systems. These programs are successfully applied by nontechnical personnel in field locations that cover 95% of Chevron's rod pumping wells. The key reasons for this success are management support as well as program features and unique capabilities designed to simplify technology application.The analysis program (SADA) uses the wave equation to model the rod string and an exact pumping unit kinematic model. SADA can perform downhole calculations even with a solid line dynamometer card. It can determine the existing counterbalance moment from crank and counterweight information along with the counterweight positions required to balance the unit.Crank speed variation and inertia torques can be considered without measuring motor speed. Furthermore, pump intake pressure, fluid level and net stroke can easily be determined from an interactive pump card analysis. An auxiliary program to SADA called EXPROD, employs a pattern recognition scheme and expert knowledge to interpret SADA 1 s results and diagnose well conditions. Results of applying this technology are presented as are recommendations for effective technology transfer.

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