Journal of Earth Energy Engineering
Latest articles in this journal
Journal of Earth Energy Engineering, Volume 9, pp 66-79; doi:10.25299/jeee.2020.4102
A heated swimming pool has long been known as a tourist destination, sports, to stress therapy. Warm water is obtained from burning fuels such as fossil fuel that is not environmentally friendly. Then technologies based on an alternative energy source is needed to be an optimal solution to the heating of a swimming pool, which can be very expensive in terms of energy demand and environment conservation. Due to the sizeable geothermal potential owned by Indonesia and only 3% of the total potential that has been successfully used for electricity generation (PLTP), therefore a design of a heated swimming pool heated by geothermal fluid was made to utilize clean and environmentally friendly energy sources in the Lembang region, West Java. The pool, which is designed to have an area of 10 x 10 m2, has a temperature of 26-30 oC and is heated by a geothermal fluid at a rate of 12.7 l/s and a temperature of 110 oC. The total heat energy utilized is 170 to 330 W/m2. Economic analysis shows an NPV of more than one and an IRR of 17% for a 10-year economic life. Hence, this warm swimming pool deserves to be developed.
Journal of Earth Energy Engineering, Volume 9, pp 102-111; doi:10.25299/jeee.2020.3922
Wax paraffin deposition is a problem faced in the pipeline for petroleum industries that they blockage the partial or full inside the pipe, which will decrease the production rate. One of the treatments is to use the preventive methods called wax inhibitors which are expected to inhibit the crystallization of paraffin wax, and bio-solvent is included. Hydrolysis and fermentation technique are used to produced bio-solvent. Hydrolysis aims to break lignin and hemicellulose, damage the crystal structure, and increase the porosity of the material. At the same time, the occurrence of pentose changes and some glucose into ethanol is present in the fermentation process. Then, purified by the distillation process to obtain bio solvent products that are applied with waxy crude oil can reduce the pour point value of crude oil. From the hydrolysis process with five variations of acid percentage, the amount of reducing sugars increase. By increasing temperature from 50 ° C to 100 ° C, the reducing sugars continues to increase until it reaches the optimal point of 18.2 ° Brix. The amount of inoculant also affects the level of bio-solvent where the optimum results using inoculants are 0.015 g/mL, which produces 6% levels of bioethanol. The high ethanol content of 2% had a density value of 0.979 g/mL. The best °API at 5% is 13.901, and the average value is about 13.0945, where the best viscosity values for ethanol content of 6% are 0.814. Bioethanol testing using waxy crude oil is carried out with the bioethanol content of 6%. The addition of the ethanol contents only decreased the pour point 2-3℃. At sample, #LGK19 experienced a 3°C drop in pour point from 45°C to 42°C. Therefore, it can be concluded that bioethanol used as a solvent can potentially inhibit paraffin deposition.
Journal of Earth Energy Engineering, Volume 9, pp 59-65; doi:10.25299/jeee.2020.5529
The source rock maturity and the hydrocarbon generation history are evaluated in the deepwater Phu Khanh Basin. The average values of heat flow, paleo water depth, and surface-water interface temperatures range from 50.80–61.69 mW/m2, 150-3,500 m, and 2.30-250C, respectively. The Oligocene and Lower–Middle Miocene source rocks are presented. The Oligocene source rock is derived from the lacustrine environment; it is mature to overmature in the Southwest part of the Phu Yen Depression. The main oil phase started in the Early Miocene, and the amount of wet gas occurred only at the bottom part. The Lower-Middle Miocene source rock has been immature in both the Southwest and Northeast part of the Phu Yen Depression. Based on the geochemical analysis, these source rocks were predominantly a mixture of type II and type III kerogens. The total organic carbon and the hydrogen index values range from 1.8-2.5 % and 250-320 mg/g, respectively. The results can help define reservoir locations for future field development planning in the Phu Khanh Basin.
Journal of Earth Energy Engineering, Volume 9, pp 88-101; doi:10.25299/jeee.2020.5264
This paper discusses a transient model of the intermittent gas lift technique in an oil well. The model is developed in the gas line, in the tubing-casing annulus, and the tubing. The line-pack and line-drafting phenomena in the gas line are considered in the model. A numerical approach will be used to solve the mathematical model that represents fluid flow during intermittent gas lift injection. The dynamics of important variables in the intermittent gas lift are investigated and analyzed to determine the best production strategy for intermittent gas lift. The variables are film thickness and velocity, slug height and velocity, and gas height and velocity. The relationships between surface injection control parameters (gas injection pressure and gas injection rate) and the velocity and height of film, gas, and liquid are shown in one cycle of the gas lift intermittent process. The higher the gas injection pressure, the faster the gas injection velocity, and the thinner the film thickness in the tubing. In order to obtain clean tubing from film thickness, the gas injection pressure needs to be optimized, which will lead to maintaining compressor discharge pressure availability. Detailed observation of the dynamic performance inside the tubing production well will give the optimum oil production rate for oil wells under a gas lift intermittent production strategy for field application.
Journal of Earth Energy Engineering, Volume 9, pp 80-87; doi:10.25299/jeee.2020.4659
Steam injection can be success in increasing oil recovery by determining the steam chamber growth. It will impact on the steam distribution and steam performance in covering hot areas in the reservoir. An injection plan and a proper cyclic steam stimulation (CSS) schedule are critical in predicting how steam chamber can grow and cover the heat area. A reservoir simulation model will be used to understand how CSS really impact in steam chamber generation and affect the oil recovery. This paper generates numerous scenarios to see how steam working in heavy oil system particularly in unconsolidated sand reservoir. Combine the CSS method and steam injection continue investigate in this research. We will validate the scenarios based on the how fast steam chest can grow and get maximum oil recovery. Reservoir simulation resulted how steam chest behavior in unconsolidated sand to improve oil recovery; It concluded that by combining CSS and Steam Injection, we may get a faster steam chest growth and higher oil recovery by 61.5% of heavy oil system.
Journal of Earth Energy Engineering, Volume 8, pp 73-94; doi:10.25299/jeee.2019.4874
This paper presents a review of electrical heating for the recovery of heavy oil which the work adopts methods used in the past and the prospects for crude oil recovery in the future. Heavy oil is one of the crude oils with API more than 22 which has the potential to overcome the current light oil crisis. However, high viscosity and density are challenges in heavy oil recovery. The method is often used to overcome these challenges by using thermal injection methods, but this method results in economic and environmental issues. The electrical heating method could be a solution to replace conventional thermal methods in which the methodology of electrical heating is to transfer heat into the reservoir due to increasing oil mobility. Because the temperature rises, it could help to reduce oil viscosity, then heavy oil will flow easily. The applications of electrical heating have been adopted in this paper where the prospects of electrical heating are carried out to be useful as guidelines of electrical heating. The challenge of electrical heating is the excessive heat will damage the formation that must be addressed in the prospect of electrical heating which must meet energy efficiency. The use of Artificial intelligence becomes a new technology to overcome problems that are often found in conventional thermal methods where this method could avoid steam breakthrough and excessive heat. Therefore, it becomes more efficient and could reduce costs.
Journal of Earth Energy Engineering, Volume 9, pp 46-59; doi:10.25299/jeee.2020.3975
Drilling activity in deep formation usually gave greater challenges to the engineer due to its high pressure and temperature. To minimize this problem, drilling mud needs to be modified into a certain condition where it should be performed well in those extreme situations. The drilling mud quality does not significantly decrease, it simply requires better quality of mud at certain points at high temperatures. Certain additives are needed to maintain their performance. Therefore, this study aims to improve the quality of drilling mud by adding additives from carbon powder originating from coconut shells. Coconut shells are burned and processed until they become nanometer-sized, then used as additives in drilling mud. Then, several analyses such as XRD, SEM, as well as the rheology of drilling mud are evaluated. XRD analysis result shows the element from the coconut shell powder was graphite. Laboratory analysis results indicate that drilling mud with coconut shell powder provides better rheological value compared to the same drilling mud without the additives. It was observed that the mud with coconut shell powder performed better at high pressure.
Journal of Earth Energy Engineering, Volume 9, pp 37-45; doi:10.25299/jeee.2020.4627
Carbon dioxide (CO2) gas injection is one of the most successful Enhanced Oil Recovery (EOR) methods. But the main problem that occurs in immiscible CO2 injection is the poor volumetric sweep efficiency which causes large quantities of the oil to be retained in pore spaces of reservoir. Although this problem can be improved through the injection of surfactant with CO2 gas where the surfactant will stabilize CO2 foam, this method still has some weaknesses due to foam size issue, surfactants compatibility problems with rocks and reservoir fluids and are less effective at high brine salinity and reservoir temperature such as typical oil reservoirs in Indonesia. This research aims to examine the stability of the foams/emulsions, compatibility and phase behavior of suspensions generated by hydrophobic silica nanoparticles on various salinity of formation water as well as to determine its effect on the mobility ratio parameter, which correlate indirectly with macroscopic sweep efficiency and oil recovery factor. This research utilizes density, static foam, and viscosity test which was carried out on various concentrations of silica nanoparticles, brine salinity and phase volume ratio to obtain a stable foam/emulsion design. The results showed that silica nanoparticles can increase the viscosity of displacing fluid by generating emulsions or foams so that it can reduce the mobility ratio toward favorable mobility, while the level of stability of the emulsion or foam of the silica nanoparticles suspension is strongly influenced by concentration, salinity and phase volume ratio. The high resistance factor of the emulsions/foams generated by silica nanoparticles will promote better potential of these particles in producing more oil.
Journal of Earth Energy Engineering, Volume 9, pp 18-36; doi:10.25299/jeee.2020.4608
There are currently two fiscal regimes designated for resource allocation in Indonesia’s upstream oil and gas industry, the Production Sharing Contract Cost Recovery (PSC) and Gross Split. The Gross Split in the form of additional percentage split is designed to encourage contractors to implement Enhanced Oil Recovery (EOR) in mature fields. Low Salinity Water Injection (LSWI) is an emerging EOR technique in which the salinity of the injected water is controlled. It has been proven to be relatively cheaper and has simpler implementations than other EOR options in several countries. This study evaluates the LSWI project’s economy using PSC and Gross Split and then to be compared to conventional waterflooding (WF) project’s economy. There are four cases on Field X that are simulated using a commercial simulator for 5 years. The cases are evaluated under PSC and Gross Split to calculate the project’s economy. The economic indicators that will be evaluated are the Net Present Value (NPV) and sensitivity analysis is also conducted to observe the change of NPV. The parameters for sensitivity analysis are Capital Expenditure (CAPEX), Operating Expenditure (OPEX), Oil Production, and Oil Price. It is found that LSWI implementation using Gross Split is more profitable than PSC. The parameters that affects NPV the most in all PSC cases are the oil production and oil price. On the other hand, in Gross Split cases, the oil production is the parameter that affects NPV the most, followed by oil price. The novelty of this study is in the comparison of project’s economy between WF and LSWI using two different fiscal regimes to see whether Gross Split is more profitable than PSC on EOR implementation, specifically the LSWI at Field X.
Journal of Earth Energy Engineering, Volume 9, pp 1-11; doi:10.25299/jeee.2020.4438
Hybrid bit is one of the innovations developed for very hard and abrasive formations such as in geothermal field. This bit eliminates the risk of losing cones, reduces tripping time, and increaseas ROP to reduce the well cost. The stage of data processing by calculating the UCS formation using D-BOS software and design optimization based on 9-7/8" bits simulations in granodiorite formations. The 1st phase was to determine the 4 best out of 7 hybrid bit designs that were selected from the highest ROP obtained, the most stable cutter cutting force, and the lowest vibration by comparing the results of FEA modeling of 1 ft drilling simulation. The 2nd phase is to choose 1 of the best from the 4 selected by doing 50 ft of drilling dynamics simulation which is assessed by directional capability, the durability, and the lowest MSE. In this study to improve drilling optimization in geothermal field, it was found that the Z616 hybrid bit design was the most optimal one. Based on 1st phase simulation, this bit was able to produce ROP of 6.38 mph, a stable cutter cutting force, very low average lateral 2.109 g and axial vibration 0.329 g. Furthermore, for the 2nd phase simulation of 50 ft, seen from the comparison of directional capability, this bit has a 0.91 deg/100 ft DLS in rotating mode, and 6.5 deg/100ft DLS in sliding mode means quite stable when drilling in rotary mode and easy to make some angle in slide mode. By its durability, the average value of lateral acceleration is 10 g, and the lateral force is 6 klbf. By MSE side, this bit also produces the lowest average MSE value of 769 psi. From the economic view, this bit can save USD 198,625 - USD 564,712 of a well cost.