Pudji Permadi

Behavior of Water Cresting Under Horizontal Wells

Complex reservoir flow problems could be better understood through a study using physical models. The purpose of this paper is to present results of an experimental study of water crest behavior under horizontal wells. This work is made in an effort to better understand the formation and growth of water crest prior to and after water breakthrough. The physical model constructed differs from others in that variation in length and position of the horizontal well can be made. Eighteen different systems with varied oil column thickness and oil viscosity were run. Particularly in systems with viscous oil, the bottom water never reached the tip end of the well even at a producing water cut of almost 100 percent. The end effects defined as the unswept oil are pronounced as the well length is reduced and as the oil viscosity is increased, Also, at high water cut, the portion of the wellbore with low productivity increases with well length. These physical occurrences have not been previously reported. Postbreakthrough performance will be presented and discussed.

Saturation exponent at various wetting condition: fractal modeling of thin-sections

Abstract A reserve estimate is strongly influenced by the value of the saturation exponent used. There has been a long standing problem in the petroleum industry as to what value should be used for a given wetting condition. This problem arises due to remarkable divergence in conclusions derived from laboratory works. A non-laboratory investigation is therefore needed to study the effect of wettability on the saturation exponent. The present study has been directed toward fractal modeling through the use of thin-sectioned core samples in determining the electrical properties. The advantage of this type of work over laboratory measurements is that it is mainly independent of the influence of rock-fluid equilibrium problems. A general equation of electrical resistivity has been developed in this study. The effects of electrical tortuosity, clay content, and rock wettability are incorporated in the equation. The present work employed twenty thin-sections of limestone and sandstones. The results show that the saturation exponents obtained range from 1.6 to 5.0. The exponent consistently increases as the wetting condition is shifted from strongly water-wet toward oil-wet. It is close to 2.0 for clean sandstones at strongly water-wet, thus supports the empirical formula of Archie. The results also demonstrate that a higher clay content leads to a lower exponent. An increased fractal dimension of pores results in a slightly higher exponent for both strongly water-wet and mixed-wet systems, but it reduces the exponent for oil-wet systems. The impact of this study is that given knowledge of in-situ reservoir wettability, one can use the saturation exponent correctly when evaluating reserve estimates.

Fast Horizontal-Well Coning Evaluation Method

Abstract Producing oil from a bottom-water drive reservoir through the use of conventional vertical wells is subject to severe water coning, leading to a low oil recovery. Indonesia has many reservoirs associated with bottom water acting as the dominant driving fluid. These reservoirs could be the target for horizontal well application in an effort to imporve the oil recovery. A production predictive tool, however, is needed to support the economic evaluation prior to implementation. The purpose of this paper is to present a new method for horizontal-well coning prediction. This attempt is made by considering that the available published correlations are based on a uniform flux model, which is not the case for most field conditions as the reservoir flow geometry is affected by wellbore hydraulics. In the present study, a one-dimensional displacement governing equation is used to develop the correlation. To account for both non-uniform flux and flow geometry, a factor derived from production history matching of a field case is introduced. This factor accounts for drainage area, well length, and well position with respect to water/oil contact. Two example applications by using other field data are given to demonstrate the applicability of the method developed. The calculation procedure is simple. The method proposed can forecast oil production and water cut versus time. These are vital for an economic evaluation and designing the capacity of water handling equipment. Results also suggest that permeability characteristics data and well placement design are of importance in the process of evaluation.

Dependence of critical porosity on pore geometry and pore structure and its use in estimating porosity and permeability

It is well recognized that the wave velocity is not only influenced by its constituent materials but also by the details of the rock bulk. This situation may bring about data points of P-wave velocity Vp measured on a large number of rock samples against either porosity or permeability of the frequently scattered although certain trends may exist. This paper presents the results of a study by employing rock samples on which ϕ, k, and Vp are measured in attempt to characterize critical porosity ϕc and its relation to other rock properties. The approach used in this study is the use of Kozeny equation. The equation is believed to account for all parameters influencing absolute permeability of porous media. A mathematical manipulation done on the equation has resulted in a power law equation that relates pore geometry √(k/ϕ) to pore structure k/ϕ3. Three different sets of sandstone amounting totally to as many as 716 samples were provided in this study. The properties measured are ϕ, k, and Vp, and grain size. For each sandstone data set, at least there are nine groups of the rock samples obtained. When Vp is plotted against ϕ, it is found that each group of each sandstone data set has both its own ϕc and an excellent relation of ϕ, Vp, and ϕc. Furthermore, combining all the basic equation for Vp, Kozeny equation, and the empirical relation for porosity results in a model equation to predict permeability. In conclusion, for the sandstones employed, ϕc is a specific property of a group of rocks having a similar pore geometry.

KINERJA MEDIA PEMBAWA UNTUK SURFAKTAN MES DARI MINYAK SAWIT UNTUK PENERAPANNYA PADA OIL WELL BORE CLEANING

The use of an antimicrobial edible coating is a technique that can be developed and applied to keep the quality and extend the shelf life of products, such as candied cherry tomato. This study purposed to get processing technology candied cherry tomatoes, to formulate edible coating with cinnamon oil as an antimicrobial, and to analyse the effect of edible coating to changes in the quality of candied cherry tomatoes during the storage process. The stages of this research were the production process of candied cherry tomatoes, which consisted of determining treatment cherry tomatoesas a whole and sliced cross, a combination of sugar concentration and immersion time in a sugar solution, and determination of drying time candied cherry tomatoes. The next steps were manufacturing and characterization of antimicrobial edible coating, and then application of antimicrobial edible coating during 12 weeks of storage. Based on the results, the best treatment processing of candied cherry tomatoes was a cherry tomato with an intact form and had 40-55-70% graded sugar concentration during 12 hours immersion time, and at 33 hours drying time. Moreover, resulted fromedible coating formula was tapioca starch, CMC, glycerol, stearic acid and cinnamon oil with percentages of 3.0%, 0.4%, 5.0%, 0.5%, and 0.6%, respectively. During storage, lowest secondary and tertiary bound water capacity on candied cherry tomatoes with an antimicrobial edible coating that was Ms of 25.32%, awsof 0.58 and Mt of 42.11%. Likewise, the lowest rate of microbial growth was from candied cherry tomatoes with an antimicrobial edible coating. Keywords: antimicrobial, bound water capacity, candied cherry tomato, cinnamon oil, edible coatingPartial oxidation pretreatment on sorghum straw using a consortium of microorganisms EM4 was done before used as raw material for production of biogas. Biogas production was performed by co-digestion method using sludge of waste water treatment plant. This research aimed to study the effect of sorghum straw and sludge ratio to the production of biogas by co-digestion method. Partial hydrolysis pretreatment using concentrations of EM4 0.0, 0.1, 0.5, and 1.0%. Pretreatment parameter measured was chemical oxygen demand dissolved (COD). The result of sorghum straw pretreatment was used as raw material for biogas production. Co-digestion method of sorghum straw and sludge was carried out by ratio variation of 80:20, 75:25, 70:30, and 65:35 (w/w). Parameters measured were cumulative biogas production (L/kg VS) and the composition of the biogas (CH4 and CO2). Results of partial oxidation pretreatment showed that the higher concentration of EM4 affected in higher levels of dissolved COD. Biogas production results by this pretreatment showed that the higher concentrations of EM4, the shorter adaptation phase of anaerobic microorganisms and higher production of biogas. The highest biogas production by co-digestion method was 371 L/kgVS, achieved by ratio of sorghum straw to sludge of 75:25 (w/w) in 65 days of fermentation. By using co-digestion method, biogas production increased 245-293%. From the results of this research note that biogas production on a pilot scale 25 L was lower than Erlenmeyer digester 0.5 L.Composition of biogas consisted of CH4 : CO2 76:26 and biogas was flammable. Keywords: sorghum straw, EM4, sludge, co-digestion, biogasCurrent technology for biodiesel production is a transesterification process of vegetable oil with metanol in batch system with the help of catalyst. The technology faces many disadvantageous for large scale, such as the requirement for rigorous stirring and purification of the product from the catalyst. Previous study showed that utilization of static mixing reactor can enhance the reaction rate and reduce the requirement of catalyst and can be operated continuously. The objective of this study was to examine the role of static mixer in reducing the catalyst requirement for the transesterification process of biodiesel production in continuous mode. Palm oleinwas used as feedstock for the transesterification process with 1:6 of mole ratio to metanol at 65oC reaction temperature. Catalyst used for the experiment was KOH with variations of 0.3% and 0.5% to the oil fed into the reactor and the numbers of static mixer modules were varied (1, 2, 3, 4, and 5 modules) to evaluate their effects to the required catalyst. As expected, the experimental results confirmed a higher conversion of the reactionby the increasing number of the static mixer modules at a specific catalyst percentage. Highest conversions obtained with 5 moduleswere 92.5% (w/w) and 88.9% (w/w), for 0.3% and 0.5% of catalyst, respectively. Analysis to the experimental results showed that 0.1% of catalyst could be replaced by the addition of 0.9 modules of static mixer, which was equivalent to 58.1 cm length ofthe used static mixer configuration. Keywords:continuous mode of transesterification, static mixing module, catalyst reduction

PRELIMINARY STUDY OF GLYCEROL ESTER USAGE AS PRIMARY AND SECONDARY EMULSIFIER ON OIL BASED MUD FORMULATION.

Vonny Indah Sari 1 , Erliza Hambali 1,2 , Ani Suryani 1,2 , Pudji Permadi 2,3 . 1. Post Graduate Program of Agroindustrial Technology, Bogor Agricultural University, Bogor 16680, West Java, Indonesia. 2. Surfactant and Bioenergy Research Center, LPPM-IPB, Padjajaran Street, Bogor 16153, Indonesia. 3. Program Study of Oil Engineering, Bandung Institute of Technology, Bandung, Indonesia. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History

Palm oil based surfactant products for petroleum industry

In petroleum production process, many problems causing reduced production are found. These include limited oil recovery, wax deposit, asphaltene deposit, sludge deposit, and emulsion problem. Petroleum-based surfactant has been used to overcome these problems. Therefore, innovation to solve these problems using surfactant containing natural materials deserves to be developed. Palm oil-based surfactant is one of the potential alternatives for this. Various types of derivative products of palm oil-based surfactant have been developed by SBRC IPB to be used in handling problems including surfactant flooding, well stimulation, asphaltene dissolver, well cleaning, and wax removal found in oil and gas industry.