مجله پژوهش نفت
پیاپی 54 (پاییز و زمستان 1385)

In this paper, the kinetic of methanol carbonylation by homogeneous Iridium catalyst with present of CH3I as promoter in acid media, has been studied. The reaction was carried out in liquid media with constant carbon monoxide pressure (22-40 atm) and temperatures of 170, 185, 195 °C. The effect of carbon monoxide partial pressure and methyl iodide promoter, acetate methyl, water and Iridium catalysts concentration on the reaction rate have been investigated. It was found that the reaction rate is dependent on the initial reactant concentrations and CO partial pressure. Based on the Arrhenius formula, the activation energy and frequency factor were calculated.

Dissolved oxygen in drilling mud acts as an accelerator and main factor in localize corrosion and degradation of drill pipes. Presence or formation of corrosive ions in chemical composition of drilling mud and precipitation of mineral scales and corrosion by products, mutually increase oxygen-induced corrosion. In the present paper, on the side of discussion on corrosion and degradation effects due to presence of oxygen in drilling mud, mechanism and morphologies of oxygen-induced corrosion on a S-135 type drill pipe is discussed.

The two major problems in handling, transportation and storage of sulphur, are dust emission and acidification. Retention of polymeric content of sulphur, Sx, results in a considerable increase in the mechanical strength of solid sulphur and decrease in friability. It is well known that naturally occurring bacteria thiobacilli oxidants, attack stockpiled sulphur or any area which stores or handles elemental sulphur and cause acidification. Treatment of sulphur with a biocide or antibacterial agent can prevent acidity development in sulphur. A new efficient method has been devised based on the use of inorganic salts.

Studies show that synthetic polymers are suitable for controlling filtration loss of laboratory muds including free clay saturated salt muds and low solid, nondispersed field muds which contaminated with cuttings and salts. High Pressure High Temperature (HPHT) filtration was kept lease than 15 cc per 30 minute by using special sulfonated polymer muds. This polymer is compatible and stable for drilling sodium & calcium salts bed formations. Heavy weight potassium treated muds were successfully tested at well site with acceptable and stable rheological properties.

The purpose of this paper is to investigate the energy consumption in H2O2 pilot plant can be saved. For this reason, the H2O2 pilot plant in Arak center of Petrochemical Research & Technology Company (NPC-RT) has been considered for investigation. First, by studying process flow diagram, the hot and cold streams and their inlet and outlet temperatures are identified. Then by using pinch technology was estimated and the heat exchanger network was designed. It was specified that the heat exchanger network has 6 process heat exchangers which by adding them in HEN, the hot and cold utility consumptions decreased about 15% and 12% respectively. By increasing the capacity up to 10,0000 tones per year the amount of pay back period decreases up to 1.7 year.

The pump shaft of a wastewater unit experienced three failures during nine-month service. The conditions of exposed wastewater and characteristics of the failed shafts were investigated. The results showed sufficient opportunity was provided for SRB microorganisms to effectively activate on the shaft surface in water-stagnant areas despite performing chemical and biological treatments on the wastewater. SRBs induced deep pits with tunneling-like structure, which created favorable conditions for stress concentration and initiation of corrosion fatigue. The morphological and characteristic features of related crack propagation on the fracture surface have been discussed.

There are several correlations used to simulate the miscible displacement process contains multiple parameters; i.e. dispersion, diffusion coefficients and accessible pore volume. Determination of these parameters is of critical importance. There are different methods for determination of accessible pore volumes that is the portion of pore volumes, which contributed to miscible process. The X-Ray and thin section analysis, network modeling, determination of pore size distribution and some statistical methods are commonly used to determine the accessible pore volumes. In this study the tracer analysis method is developed to determine the accessible pore volume. For this purpose, a series of tracer analysis tests were performed to determine the effluent concentration profile. Using the slope of the concentration profile and the solution of convection-dispersion equation, the accessible pore volume of the porous media can be calculated. To check the results, a series of miscible displacement tests were also conducted. Results show a good agreement between experimental values and analytical solution of the miscible displacement.

For optimum operation of fired heaters in oil and gas process industries, recognition of effective parameters in decrease or enhencement of efficiency is required after full consideration of the process industries, heater’s structure and method of efficiency calculations .In addition to concentration on combustion process in heaters for efficiency enhancement, activities such as on time technical inspection,compelete and precise maintanance and repairment schedual can be led to heaters with efficient operation during three years services.