According to field data, there are several methods to reduce the drilling cost of new wells. One of these methods is the optimization of drilling parameters to obtain the maximum available rate of penetration (ROP). There are too many parameters affecting on ROP like hole cleaning (including drillstring rotation speed (N), mud rheology, weight on bit (WOB) and floundering phenomena), bit tooth wear, formation hardness (including depth and type of formation), differential pressure (including mud weight) and etc. Therefore, developing a logical relationship among them to assist in proper ROP selection is extremely necessary and complicated though. In such a case, Artificial Neural Networks (ANNs) is proven to be helpful in recognizing complex connections between these variables. In literature, there were various applicable models to predict ROP such as Bourgoyne and Young’s model, Bingham model and the modified Warren model. It is desired to calculate and predict the proper model of ROP by using the above models and then verify the validity of each by comparing with the field data. To optimize the drilling parameters, it is required that an appropriate ROP model to be selected until the acceptable results are obtained. An optimization program will optimize the drilling parameters which can be used in future works and also leads us to more accurate time estimation. The present study is optimizing the drilling parameters, predicting the proper penetration rate, estimating the drilling time of the well and eventually reducing the drilling cost for future wells.
Three different types of surfactants containing an anionic, a cationic and a new nonionic biosurfactant, Zizyphus Spina-Christi extract were used for the purpose of oil recovery in a core flood system. Core flooding tests were conducted on sandstone to test the effectiveness of surfactants in tertiary oil recovery. Extensive research including adsorption behavior of surfactants on the rock surface and interfacial tension (IFT) measurements were used to analyze the surfactant flooding performance. An additional recovery varying between 6.15 % and 12.17 % of original oil in place (OOIP) was obtained by surfactant solution injection. The results indicated that the new biosurfactant can be used as an enhanced oil recovery (EOR) agent either for IFT reduction or wettability alteration purpose. Furthermore, availability and the low cost of the Zizyphus Spina-Christi extract in comparison to common chemical surfactants in petroleum industry make it economically viable for surfactant flooding.
To obtain reliable analytical values of sulfur in fuels, sulfur standard solutions must be prepared accurately. A sulfur certified reference material in high purity sulfur compound, NMIJ CRM 4221-a (dibutyl sulfide), has been issued by National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (NMIJ, AIST). The purity of dibutyl sulfide was determined by a freezing point depression method and a mass balance method. The certified value for sulfur content (mass fraction) was based on the purity, molecular weight, atomic weight, and impurities containing sulfur. The certified value (sulfur content) and its expanded uncertainty (k = 2) are 0.21919 kg kg−1 and 0.00006 kg kg−1, respectively. The details of procedures for determination of the certified value are reported here.
The carbonyl-ene reaction of olefin with formaldehyde is an important reaction in organic synthesis. In this study, the carbonyl-ene reaction of olefin with formalin was carried out in water, using H-beta zeolite as a solid acid catalyst. H-beta zeolite was found to be an effective catalyst for the carbonyl-ene reaction of styrene with formalin at a reaction temperature of 90 °C to produce 4-phenyl-1,3-dioxane derivatives in excellent yield, and for the carbonyl-ene reaction of α-methylstyrene with formalin at a reaction temperature of 20 °C to produce homoallylic alcohol with good selectivity. The H-beta zeolite catalyst could be easily recovered and reused.
Although it is expected that torrefaction of empty fruit bunch (EFB) from Malaysian palm oil mill will provide a useful energy recovery source, a detailed analysis of the process has not yet been conducted. In this study, a process evaluation is made for the three cases of palm mill EFB torrefaction in terms of energy and operating cost. Most of the energy requirement for the torrefaction is heat needed for EFB drying and heat of reaction for the torrefaction. In the first case all the heat is supplied by heavy oil. In the second case flue gas from a palm oil mill boiler is employed for drying. In the third case Vapor Re-Compression (VRC) for heat recovery is employed in the drying process. Mass and energy balance calculations reveal that energy saving by VRC largely improves the energy efficiency. In spite of the initial cost increase and electricity cost requirement, the VRC process results in the lowest unit cost of the torrefied product due to the large reduction of heavy oil consumption.