Geological Structure and Tectonic Reconstruction of Botutonuo and Surrounding Areas, Gorontalo

<p class="Normal1"><em><span>The research aimed to reconstruct the geological structure and tectonics based on fault, shear fracture and veins data of the Botutonuo and surrounding areas. This research was conducted with DEM interpretation method to determine the lineament pattern of rock offsets and the geological structure mapping method. Geological structure analysis was carried out by using kinematic analysis method of fault, fracture and veins data using the Win Tensor program to obtain the direction and type of stress forming it. Based on the results of the analysis, extensive stress and transtensive stress trendingN-S resulted direction of Normal Fault and Slip Fault (NE-SW). Extensional stress trending (NE-SW) is the result of reorientation stress trending (N-S) in the North Sulawesi arm which is accommodated by the Gorontalo Fault regime. Normal fault and slip fault are the 2nd order faults of the 1st order faults of Gorontalo faults.</span></em></p>

Analysis of Siphon String Application to Optimize Gas Lift Injection

<p><span style="font-size: small;"><span style="font-family: Times New Roman;"><em>B-</em><em>X</em><em> well is an oil producing well at Bravo field in Natuna offshore area, which was completed at IBS zone using 5-1/2 inch tubing size. </em><em>However, after several years of production period, the well’s production rate decreased due to reservoir depletion, and experienced gas lift performance problem indicated by unstable flowing condition (slugging flow). In year 2020, Siphon String installation is applied to the well in order to give deeper point of gas lift injection and better well’s production. The additional advantage by having smaller tubing size (insert tubing) is to reduce the slugging flow condition. The analysis of this siphon string installation at the B-X well, technically will be performed by evaluating gas lift performance and the flow regime inside the tubing using a Well Model simulator. The simulation was developed based on the real well condition. Several sensitivity analysis were done through several cases such as: variation in depth of gas lift point of injection, and the length of the siphon string. The simulation was required to evaluate the effectiveness of the existing installation, and to give better recommendation for the other well that has the same problem. The result indicates that the depth of the current siphon string installation has been providing the optimum production rate, while the slugging flow condition will still be occurred at any given scenario of the siphon string depth due to the very low of well’s productivity. The similar procedure and evaluation can be implemented to other oil wells using gas lift injection located either in offshore or onshore field. </em></span></span></p><p><em><span style="font-family: Times New Roman; font-size: small;"> </span></em></p><p><em><span style="font-family: Times New Roman; font-size: small;">Keywords: Production Optimization, Siphon String, Flow Regime</span></em></p>

Analysis of the Quality of Mixed Coconut Shell Waste Briquettes with Various Biomass Additives as Alternative Fuels

The purpose of this study was to see the best quality of briquettes from the main ingredient of coconut shell waste<br />with various biomass additives to see the calorific value, moisture content, ash content, and volatile matter<br />content of the biomass mixture. Furthermore, further research will be carried out specifically to see the quality of<br />briquettes from a mixture of coconut shell waste and sawdust. The method used in this research is to conduct a<br />literature study of various literature related to briquettes from coconut shell waste mixed with various additives<br />specifically and then look at the best quality briquettes produced from these various pieces of literature. As for<br />what is determined as the control variable of this study is coconut shell waste and as an independent variable,<br />namely coffee skin waste, rice husks, water hyacinth, Bintaro fruit, segon wood sawdust, coconut husk, durian<br />skin, bamboo charcoal, areca nut skin, and leather waste. sago with a certain composition. Furthermore, this<br />paper also describes the stages of making briquettes from coconut shell waste and sawdust for further testing of<br />the calorific value, moisture content, ash content, volatile matter content on a laboratory scale for further<br />research. From various literatures, it was found that the highest calorific value was obtained from a mixture of<br />coconut shell waste and bamboo charcoal with a value of 7110.7288 cal / gr and the lowest calorific value was<br />obtained from a mixture of coconut shell waste and sago shell waste with a value of 114 cal / gr, then for the value<br />The highest water content was obtained from a mixture of coconut shell waste and rice husk with a value of<br />37.70% and the lowest water content value was obtained from a mixture of coconut shell waste 3.80%, then for the<br />highest ash content value was obtained from a mixture of coconut shell waste and coffee skin with a value of<br />20.862% and for the lowest ash content value obtained from a mixture of coconut shell and Bintaro fruit waste,<br />namely 2%, and for the highest volatile matter content value obtained from a mixture of coconut shell and coconut<br />husk waste with a value of 33.45% and for the value of volatile matter levels The lowest was obtained from a<br />mixture of coconut shell waste and sago skin waste with a value of 33 , 45%.

Calculation of Limestone Reserves in the East Biluhu Region, Gorontalo district, Gorontalo Province

<em>Indonesia is a country that has a lot of natural resources. Natural resources are widely used in various areas of human life. One of the resources that is often used is limestone. Limestone is a non-metallic mining material that has considerable potential and reserves and spreads across almost all parts of Indonesia, but the exact amount of reserves is not yet known. The research aims to predict the amount of packstone-type limestone reserves using geophysical methods. This research was conducted using the geoelectric method with the Schlumberger configuration, where the resistivity geoelectric data obtained variations in resistivity and layer thickness. From this data, it is then interpreted to determine the type of rock in the surface area, and making a 3D model to determine the distribution of limestone in the study area and to calculate the amount of limestone reserves in the study area. Based on the research results, it is known that the research area is dominated by packstone with a resistivity value of 16.6 Ωm - 1.3x105 Ωm. The calculation result of packstone reserves in the study area is </em>73,629,403<em>tons.</em>

Effect of Sand Grain Size on Spontaneous Imbibition of Surfactant Solution

<em><span>In spontaneous imbibition researches, surfactant has been employed to control interfacial tension (IFT) and wettability. In this paper, the evaluation of grain size effect on spontaneous imbibition of surfactant solution is presented. In this work, the synthetic porous media (sand packs) with uniform and non-uniform grain size from 30 mesh to 100 mesh were made. The porous media were initially saturated by oil. Then they were immersed in brine with salinity of 62 to 40,000 ppm for 24 hours. After that, the porous media were immersed in surfactant solution with concentration of 0.2% for another 24 hours. The total oil recovery during these treatments was measured. The experiment was separated into three parts in order to investigate the effect of uniform grains, non-uniform grains, and salinity in spontaneous imbibition. The results show that grain size and porosity were proportional to oil recovery. In the case of porous media with uniform grain size, the effect of grain size on recovery factor is stronger than that of porosity. Meanwhile the salinity has an the optimum condition for </span><span lang="EN-US">a maximum </span><span>recovery factor. In this study, it happened at salinity of 20,000 ppm.</span><span> <span lang="EN-US">Oil recovery factors observed in this study ranged from 66.7% to 91.1%.</span></span></em>

Fatigue Failure Analysis of Bottom Hole Assembly during the Drilling of H-E1 and H-Q1 Wells in the Hululais Geothermal Field

<p><em>In drilling operations it is intended to be able to conduct drilling quickly without causing damage to the drilling equipment and be able to produce good quality wells. Failure on the drilling pipe or bottom hole assembly (BHA) ranks results from loading that exceeds the maximum strength limit of the material. In this study, the calculation of the load on the downhole motor, where in the depth of the drill 512 meters failure occurs in the form of broken downhole motor. Based on the analysis conducted, at a depth of 494 meters the value of the hookload has increased quite high at 131.8 klb, while the maximum allowable hookload value is 121 klb, this indicates an overpull of 10.8 klb and based on the calculation of the drag value, a drag is obtained 38.8 klb while the maximum drag value is 28 klb, the difference between the actual drag value and the maximum allowable drag value is 10.8 klb, so it can be concluded that the failure that occurs in BHA # 10 is due to a drag that exceeds the maximum limit of 10.8 klb.</em><em></em></p>

Comparative Analysis of Indonesia Gross Split PSC with Fiscal Terms of Several Southeast Asian Countries

<em>The implementation of the Gross Split PSC in the upstream oil and gas industry in Indonesia has been running since 2017 with the hope of being able to accelerate the decision-making process and increase attractiveness for oil and gas investors. This study is to analyze the implementation of Indonesia Gross Split PSC compared to other fiscal terms in Southeast Asia region from an economics perspective. The comparisons reviewed are between Indonesia Gross Split PSC and the following fiscal terms: Indonesia Cost Recovery PSC, Malaysia R/C PSC, Thailand Concession, and Vietnam PSC. Fields used as input for analysis are producing oil fields with small-scale recoverable reserves according to RF-2005 / SPE, namely Block X (early production fields) and Block Y (terminated fields). From economics calculations and comparisons, sensitivity and profitability characteristics, specifically applied to the field conditions under review, it is concluded that Indonesia Gross Split PSC has improved economics indicators compared to Indonesia Cost Recovery PSC so that Indonesia Gross Split PSC has an economics level indicator that is better than PSC Indonesia Cost Recovery when compared to Malaysian R/C PSC, Thailand Concession and Vietnam PSC.</em>

Identification of Cementing Quality and Hydraulic Seal at Hydrocarbon Zone in F Field

<em>Cement analysis needs to be done on wells that have decreased production and there is additional water production. The longer the well is produced, the water will approach and even reach the perforation zone which results in the water being produced. Several steps must be proposed in knowing and handling water production in wells, in addition to collecting data from wells and reservoirs in full, analysis of problems related to mechanics such as cementing analysis needs to be done to determine the possibility of leakage, microannulus or channeling. The method used is quantitative, by comparing the amount of water production in two wells and its relation to the hydraulic seal formed in the cement. The analysis was carried out on two wells, namely F-3 and F-4. F-3 wells produce large amounts of water, namely 1168 BWPD. This is possible considering the position of this well adjacent to the water zone. And based on the analysis carried out, the hydraulic seal on the F-3 well has not yet been formed making it possible for direct contact between the productive zone and the water zone. Water production in F-4 wells is 35 BWPD. The low water production in these wells can also be assumed due to the formation of hydraulic seals in cementing. Looking at the data above, it can be concluded that without the formation of hydraulic seals on the F-3 wells, secondary cementing needs to be done to close the cementing which is not good so that there is no leakage anymore and there is no communication between the productive zone and the water zone.</em>

Evaluation of Hydraulic Jet Pump Application in Sembakung Field

<em>Sembakung Field is an "brown" remote oil and gas field located in North Kalimantan with very limited road infrastructure to and within the location. The purpose of this study is to evaluate the performance of Hydraulic Jet Pump for field development as well as to assess the opportunities for incresing oil production by applying the Hydraulic Jet Pump in the fields. Quantitative data are used and evaluated to investigate the pump design and actual pump performance by considering transient and steady state conditions. The research is performed for three wells. There was significant difference between design and actual flowrate due to the transient and steady state conditions. Steady state condition was achieved within four to seven months in this field. Based on the evaluation results it can be concluded that the application of hydraulic jet pump is proper for Sembakung Field and there is opportunitiy to increase oil production rate by applying the pump type in the field.</em> <em>The application of the hydraulic jet pump during the period can produce 78 bpd to 112 bpd of oil with liquid production rates ranging from 130 bpd to 980 bpd.</em>

The Effect of Thixotropic Additive on the Properties of the G Class Cement

<em>In oil, gas, and geothermal drilling activities, the casing cementing process is always carried out in order to fulfill its function properly and safely. Therefore, everything that supports these activities must be carefully thought out. Before the actual cementing process is applied in the oil, gas, and geothermal field, laboratory-scale simulation must first be carried out by conducting experiments and testing several formulations of cement, water mixture, and additives to be used. The author chooses thixotropic additives, besides functioning as an accelerator, thixotropic can also strengthen the cement itself. With a number of experiments, an optimal cement slurry composition formulation will be obtained, in the sense that by using as few additives as possible, the requirements of the physical characteristics will meet the required standards for conditions (temperature and pressure) of the formation in the well to be cemented. All cementing activities are expected to run well, smoothly, and on time.</em>