<p class="IEEEAbtract"><em>Polymer injection is one of the methods of increasing oil recovery or Enhanced Oil Recovery (EOR) after the water injection method is performed, to reduce residual oil saturation. The polymer reduces the water mobility ratio so that the sweeping efficiency will increase to encourage bypassed and unswept residual oil saturation. For polymer injection applications, partially hydrolyzed polyacrylamide (PHPA) or commercially known as HPAM is the most widely used type. At the current low oil prices, design optimization of polymer injections in certain reservoirs is important. The purpose of this research is to analyze the effect of permeability and polymer concentration on residual oil saturation by core flooding method in the effort of optimization of polymer injection. The optimal concentration in this study is 1,500 ppm which has the lowest residual oil saturation value. The increase in concentration from 500 ppm to 1.500 ppm, residual oil saturation decreased in four variations of Berea sandstone permeabilities. However, when the polymer concentration is added to 2.500 ppm, the residual oil saturation value increases. This can be caused by pore clogging. Whereas with permeability, residual oil saturation is directly proportional. The greater the permeability the greater the value of residual oil saturation. Core Y7 Berea has the highest permeability and saturation of residual oil. The results of this study are expected to be useful in the development of polymer injections on EOR activity.</em><em></em></p><p><strong><em>Keywords.</em></strong><em> </em><em>polymer injection, concentration, permeability, PHPA, residual oil saturation</em><em></em></p>

Abstract. This paper perfoms a discussion of the result from two laboratory tests of surfactant injection. The first test is focused on the influence of salinity that varies between 5000 ppm-9000 ppm with a concentration of 1% surfactant to the value of density, viscosity, interfacial tension, and Recovery Factor. The second test is performing the influence of surfactant concentration that varies between 0.1% -1% with a value of 5000 ppm salinity to the value of residual oil saturation, density, viscosity, and interfacial tension. The result of the first test shows that along with the increase of salinity levels, the increase in viscosity and density will occured as well. However, variations in salinity does not affect to the value of interfacial tension. Meanwhile, on Recovery Factor testing, the Recovery Factor optimal value of 61.53% was obtained when the salinity levels 6,000 ppm. The result of the second test showed that the addition of surfactant concentration lead to a decrease in the residual oil saturation and interfacial tension, but it may cause an increase in density and viscosity.

<p><strong>Aims</strong><strong>:</strong> This study aimed to increase the utilization of biomass-derived from the waste of coconut and peanut shells by making them as briquettes, as an alternative to fuel. The scarcity of petroleum because of its increasingly limited existence encourages all parties to take part in the development and discovery of new alternative energies. This is expected to overcome one of the most important of the many problems facing this country. The method used in this research is to start with a literature study of materials from various sources about the benefits and manufacturing of briquettes from biomass waste as an alternative energy source to be further tested for quality.  This involves a heat test, water content test, ash content test and determination of the flying matter. <strong>Results</strong><strong>:</strong> The test results showed that natural gas emissions were below threshold, namely 0-30 ppm CO, 0-3.6 ppm H₂S, and undetectable NO_x. After evaluation, the results showed that with the addition of 30% of the biomass, the ignition time was reduced and the remaining unburned briquettes or bottom ash was reduced by 68.68%. <strong>Conclusion, significance, and impact of study:</strong><strong> </strong>The results help the community and the parties involved related to appropriate bio briquettes technology. It also eventually becomes one of the solutions to assist the government in solving problems related to alternative fuels to petroleum.</p>

<p><strong>.</strong><em> </em>Hydraulic fracturing is one of the stimulation method that aimed to increase productivity of well by creating a high conductive conduit in reservoir connecting it to the wellbore. This high conductivity zone is created by injecting fluid into matrix formation with enough rate and pressure. After crack initiate and propagate, the process continue with pumping slurry consist of fracturing fluid and sand. This slurry continues to extend the fracture and concurrently carries sand deeply into formation. After the materials pumped, carrier fluid will leak off to the formation and leave the sand holds the fracture created. TLS Formation in X and Y Field is widely known as a formation that have low productivity since it has low permeability around 5 md and low resistivity 3 Ohm-m. Oil from TLS formation could not be produced without fracturing. This formation also have high clay content, 20 – 40 % clay. Mineralogy analysis also shown that this formation contains water sensitive clay such as smectite and kaolinite. Hydraulic fracturing has been done in this field since 2002 on around 130 wells. At the beginning of hydraulic fracturing campaign, the success parameter is only to make the wells produce hydrocarbon in economical rate. As the fractured wells become larger in number, several optimization is also been done to increase oil gain. Later on, the needs of conclusive analysis to evaluate well performance after hydraulic fracturing rise up due to sharp decrement of crude oil price. Accurate analysis and recommendation need to be conducted to assess the best candidate for hydraulic fracturing to maximize success ratio. Even though a common practice, candidate-well selection is not a straightforward process and up to now, there has not been a well-defined approach to address this process. Conventional methods are not easy to use for nonlinear process, such as candidate-well selection that goes through a group of parameters having different attributes and features such as geological aspect, reservoir and fluid characteristics, production details, etc. and that’s because it is difficult to describe properly all their nonlinearities. In that matter, Artificial Intelligence approach is expected to be an alternative solution for this condition.</p>

Super-absorbent polymer (SAP) is able to absorb water by multiple times more than its own weight. Sugarcane bagasse (SCB) raw material has been excessively produced as a byproduct in sugar factory. The synthesis of SAP from SCB creates a balance between the utilization of industrial by-product and the resulted environmentally friendly material. In oil production water might be a troublesome, thus minimizing water production while extracting oil is essential. Besides, diversion of the flow in heterogeneous reservoir optimizes the oil production. SCB-SAP might have the potential to act as a water absorbing agent and flow diverter by taking the advantage of SAP high swelling ratio characteristic. This study provides the information of SCB-SAP synthesis methods and highlights the current application of SAP in oil industry, including the laboratory studies and field tests.

<em>In this research, bagasse NaLS surfactant was used as an injecting reservoir fluid at low salinity. The purpose of this study was to observe the effect of IFT and thermal stability on oil recovery factors in various compositions. The material used in this study isbagasse based NaLS surfactant, light oil and sandstone, while spinning drop is used to measure the interface tension. The oven was used for thermal stability testing and core flooding equipment for the surfactant injection. The success in this study was based on the value of the recovery factor, the small IFT value, and stability of IFT in the thermal stability test. The IFT results obtained for CF1, CF5,and CF7 were 10.4 mN / m, 4.09 mN / m, and 4.34 mN / m, respectively. Based on The results of the thermal stability test only the CF7 was stable with an IFT value of 2.11 mN / m, while the other two variations were unstable. The recover factor of CF1, CF5, and CF7 was 3.24%, 3.52%, and 5.34%, respectively. It can be concluded that IFT as well as thermal stability affect the frecovery factor.</em>

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<em>Drilling activity has been focused in time on each activity to reach target depth (TD) immediately and efficient in cost. The priority also aimed to Geothermal drilling by doing specific measurement on Invisible Lost Time (ILT) as new focus to perform. Time becomes main aspect which it would affect the cost, therefore it is important to complete the well in time manner. The research was done to analyze the offset well of well A, B, C and D in order to identify Productive Time and Non Productive Time. Key Performance Indicator (KPI) has been identified from each activity also targeted from two wells of well B dan Well D due to time efficiency used during operation. The method used by comparing offset wells then continue to identify each KPI by measuring each activity based on ASCII time and Daily Drilling Report (DDR). The result from offset wells showed inefficiency in time with Flat time 49%, Drilling 42% and non-flat time (NPT) 9% from 28 days without completion. KPI based on the crew performance has confirmed that day shift crew performed better than night shift crew. KPI on rate of penetration (ROP) on day shift crew at 6 m/hr and night crew at 3 m/hr. KPI on Weight to Weight on day shift crew at 28.43 minute/stand faster than night shif crew at 34.65 minute/stand. KPI on Tripping in cased hole on day shift crew at 4.5 minute/stand faster than night crew shift at 4.6 minute/stand. KPI on Tripping in open hole on day shift crew at 2.7 minute/stand faster than night shift crew at 3.7 minute/stand. KPI on Tripping out open hole on day shift crew at 3.0 minute/stand slower than night shift crew at 2.8 minute/stand. KPI on Tripping out cased hole on day shift crew at 3.36 minute/stand faster than night crew shift at 3.74 minute/stand. ILT from both wells to 20 % or 5 days inefficiency on each well. It detects of potential savings to 10 billion rupiah from both wells.</em>