Direct Utilization of Geothermal Energy in Menengai, Kenya: Pilot Project for Drying Food Commodities in Lesiolo, Nakuru

Kenya is a developing country highly dependent on economic rotation in agricultural sector with main commodities corn, tea and fruits. In order to maintain quality of commodity within a certain period, a drying process is needed. Purpose of drying is to reduce moisture content of a commodity to a certain level. Alternative energy that can be used for drying activities in Kenya is geothermal energy. In assessing direct utilization of geothermal energy, a pilot project was made in Lesiolo, Nakuru by utilizing heat energy from the Menengai geothermal waste fluid area, Nakuru. Drying process can utilize brine from separator or condensate from power plant by using a heat exchanger to get required drying temperature. One drying room can hold about 20 tons in ambient air conditions. This dryer is shaped like a tunnel where hot air will flow from each side of drying chamber. Food commodities used in this project are wheat, corn and barley. Heat energy needed to dry each of these food commodities comes from geothermal waste fluid that enters heat exchanger with a minimum input temperature of 130oC and an output of 93oC. Mass flow rate needed to dry every 30 m3 of commodity is 2 kg/

Skenario Pengembangan Sumur Injeksi pada Sumber Daya Panas Bumi Sistem Dominasi Air dengan Pemodelan Reservoir 3D Dinamik

Reinjeksi fluida memiliki peran penting dalam pengelolaan reservoir panas bumi. Reinjeksi bertujuan untuk meningkatkan pengisian alami ke reservoir untuk menjaga tekanan reservoir, produksi uap, dan mengekstraksi lebih banyak panas dari reservoir. Penginjeksian kembali harus direncanakan dengan baik untuk menghindari masalah seperti terobosan termal. Pemodelan dinamis reservoir panas bumi dapat digunakan untuk mengidentifikasi kondisi awal reservoir, karakteristik produksi, dan kinerja produksi reservoir di masa depan. Dalam studi ini, reinjeksi ke reservoir yang didominasi air sintetis direncanakan untuk mempertahankan 55 MW produksi listrik selama 30 tahun. Tujuan dari penelitian ini adalah untuk menentukan strategi injeksi terbaik untuk mencapai produksi listrik selama 30 tahun. Berbagai skenario produksi-injeksi diuji menggunakan pemodelan reservoir panas bumi 3D dinamis. Studi ini menunjukkan bahwa lokasi dan laju injeksi adalah parameter utama dalam strategi injeksi. Sumur reinjeksi terletak di dalam reservoir, tetapi pada jarak yang cukup untuk menghindari terobosan. Suntikan area dekat produksi menyebabkan terobosan dalam sumur produksi. Injeksi pada tingkat yang lebih tinggi memperlambat penurunan tekanan dan meningkatkan produksi cairan secara signifikan.Reinjection aims to increase the natural recharge to reservoirs in order to maintain the reservoir pressure, steam production, and extract more heat from the reservoir. Reinjection must be well planned to avoid problems such as thermal breakthrough. Dynamic modelling of geothermal reservoirs can be used to identify the future production performance of the reservoir. In this study, reinjection to a synthetic water-dominated reservoir is planned to maintain 55 MW of electricity production for 30 years. The purpose of this study is to determine the best injection strategy. Various production-injection scenarios are tested. The study shows that location and injection rate are the key parameters in injection strategy. The production well are located inside the reservoir, but enough distance to avoid a breakthrough. Near-production area injections are causing breakthrough in production well. Injection at higher rates slows down pressure decline and increase the fluid production significantly

Heat Loss and Cost Reduction of Insulation Materials on Geothermal Pipes

Power plant in X field has 6 production wells with steam dominated reservoir type. Fluid flowing in pipe from the well to the plant experienced heat loss that occured due to difference in the temperature of the flowing steam and the outside that caused heat transfer from inside the pipe to the outside. Minimizing heat transfer can be done by using an insulator is installed on the outside of the pipe, in this case, Foamglas W+F Insulation  The method to assess the heat loss is by calculating material properties as well as fluid properties to deterimine heat transfer rate for one well as representation of all wells. From the calculation, it can be concurred that the use of Foamglas W+F Insulation material provides reduction in heat loss of 113,61 kWh for one well with significant reduction in costs of 1.035 billion IDR per well per year. By comparing the heat loss reduction value which is almost the same, the option to replace the materials to Foamglas W+F insulation material is cheaper than adding the existing insulation thickness

ANALISA STABILITAS LUBANG BOR TRAYEK 12 ¼”, DENGAN PENDEKATAN MUD PROPERTIES DAN SHALE CHARACTERISTICS SUMUR “LH-3” LAPANGAN ”LENHAR”

Salah satu masalah dalam operasi pemboran adalah ketidakstabilan kondisi diameter lubang bor, dimana lubang bor dapat membesar dan bertambah kecil dari ukuran yang diinginkan yaitu diameter bit yang digunakan. Ketidakstabilan lubang bor tersebut disebabkan oleh dua faktor yaitu Uncontrollable (Natural) Factors, dan Controllable Factors. Ketidakstabilan lubang bor tersebut mengakibatkan sejumlah masalah antara lain: Pembesaran lubang bor (Oversize hole), Penyempitan lubang bor (Undergauge hole), Pipa terjepit, dll. Dalam mengidentifikasi jenis penyebab ketidakstabilan lubang bor yang terjadi di Sumur LH – 3, metode yang digunakan sebagai pendekatan masalah pada ketidakstabilan lubang bor adalah analisa terhadap data drilling report, aspek lumpur, aspek lithologi formasi, drilling parameter, dan aspek geometri lubang bor sehingga akan diketahui faktor penyebab dari ketidakstabilan lubang bor pada sumur LH-3. Hasil dari data drilling report didapat indikasi/ tanda-tanda pada saat lubang tidak stabil sampai menyebabkan pipa terjepit. Dari aspek lumpur pemboran akan dilakukan pengujian laboratorium bahan utama pembuat lumpur (bentonite) dan lumpur yang disirkulasikan, yaitu lumpur tidak memenuhi API spec. Sedangkan aspek lithologi dari analisa MBT dan XRD menunjukan formasi mempunyai karakter brittle/ mudah runtuh. Dari aspek drilling parameter dilakukan analisa terhadap WOB menunjukkan WOB yang digunakan terlalu tinggi, sehingga lubang tidak terbentuk dengan sempurna. Dari aspek geometri lubang bor maka akan diperoleh hasil dog leg yang ada lebih besar daripada dog leg saveritynya yang cenderung menghasilkan belokan yang mendadak yang dapat menyebakan terkikisnya dinding lubang bor sehingga dinding lubang bor mengalami runtuh

EVALUASI DESAIN CASING SUMUR EXISTING UNTUK REKOMENDASI SUMUR USULAN LAPANGAN “VILA” DENGAN MENGGUNAKAN METODE MAKSIMUM LOAD

Lapangan “VILA” memiliki 2 sumur existing yaitu sumur “VILA-1” dan “VILA-2” selanjutnya akan dilakukan pengeboran dengan 5 sumur usulan diantaranya sumur “VILA-3”, “VILA-4”, “VILA-5”, “VILA-6”, “VILA-8”. Pada sumur exsiting Lapangan “VILA” grade casing yang digunakan kurang optimal, dimana tidak memperhatikan kandungan CO2 dan H2S yang terdapat pada formasi yang ditembus. Evaluasi dilakukan untuk mendapatkan casing design yang optimal dan memenuhi syarat secara teknis, untuk acuan dalam perencanaan casing design sumur selanjutnya.Penentuan casing setting depth dilakukaan untuk mendapatkan dudukan casing yang kuat agar selama proses pemboran maupun produksi berlangsung lubang bor tetap aman. Penempatan casing setting depth yang kurang tepat dapat menyebabkan casing tidak kuat menahan beban yang diterima. Evaluasi casing design menggunakan metode maximum load terhadap beban – beban yang bekerja pada casing, seperti beban burst, collapse, tension, dan biaxial. Pemilihan grade casing yang tidak tepat dapat menyebabkan pecah atau meledaknya casing akibat tekanan burst atau collapse, serta casing mengalami deformasi permanen akibat beban tension yang melebihi minimum yield strength-nya. Hasil dari evaluasi casing design dimana conductor casing dilakukan drive to revusal (0-49,2 ft), surface casing (0-984 ft) menggunakan casing K-55; 106,5 ppf; BTC; R3, intermediate casing terdiri dari 2 section, section 1 (0–2500 ftTVD) menggunakan casing L-80; 72 ppf, BTC; R3, section 2 (2500-3936 ftTVD) menggunakan casing P-110; 80,7 ppf, BTC; R3, production casing terdiri dari 2 section, section 1 (0–5028,7 ftTVD) menggunakan casing L-80; 47 ppf, BTC; R3, section 2 (5028,7-7543 ftTVD) menggunakan casing N-80; 58,4 ppf, BTC; R3 dan lineer casing (7511,2–8968 ft) menggunakan casing SM22CR-110; 41 ppf; PE. Tekanan parsial kandungan CO2 dan H2S pada formasi Talang Akar sebesar 124,62 atm dan 0,01 atm dan Basement masing- masing adalah 144,17 atm dan 0,01 atm yang mengharuskan penggunaaan material non-API. Grade casing yang dipilih telah dilakukan perhitungan analitis dan didapatkan safety factor yang memenuhi standar. Kata Kunci: burst; casing design; collapse; kandungan CO2 dan H2S; tensio

3D Natural State Modeling of Mount Iyang-Argopuro Geothermal Area, East Java, Indonesia

Mount Iyang-Argopuro is one of the geothermal working areas in the East Java. Mount Iyang-Argopuro has the potential of 185 MWe of reserves and 110 MWe of resources.  It is estimated to have a liquid dominated reservoir with temperature up to 250-275 oC. An early 3D natural state numerical model of Mount Iyang-Argopuro Field is created using TOUGH2 simulator in order to identify the undisturbed condition of reservoir and resource assessment. Since Mount Iyang-Argopuro geothermal area is still in the exploration stage, the model created based on based on geological, geophysical, and geochemical data. The model has an area 14 km x 8.2 km and 9180 m in thickness. The model consists of 7410 of rectangular cell blocks with the roughest cell size is 1000 m x 1000 m and the finest is 200 m x 500 m. The model is verified by matching the model temperature and pressure profiles to the calculated geothermometer temperature and pressure, which shows good match enough

Application of Fracture Barrier Analysis in Well Stimulation Planning for Upper Baturaja Limestone Formation Based on Well Log & Drill Cutting Data from OBF-01 and OBF-04 Wells, Offshore Southeast Sumatra

In general, the South Sumatra Regional Stratigraphy of the Baturaja Limestone Formation facies is deposited on the Buildup Carbonate (Reef) and the Limestone Clastic Carbonate of the Baturaja Formation which grows as a buildup reef on the platform in the Basement High (Horst) underneath is the Lemat Formation volcanic deposits. Referring to the facies model in general, the Baturaja Limestone Formation, the depositional environment starts from Shelf Lagoon Open Circulation - Winnowed Edge Sand - Organic Buildup - Fore Slope - Deep Shelf Margin - Open Sea Shelf - Basin, meaning that carbonate is formed starting from pure organic Cabonate Buildup Reef without / a little sludge / mud to the Carbonate Basin where more muddy / mud is present, this condition causes clay minerals to also more and more mix with Terigenous Clastics (Quartz, feldpar). The complexity of the Baturaja Limestone Formation requires fracture barrier analysis associated with well stimulation planning in order to increase oil productivity with the appropriate method.   Fracture barrier fracture analysis is an approach method to determine the depth interval that becomes a barrier in hydraulic fracturing by correlating the results of geomechanical analysis from well log data and mineralogical analysis from drill cuttings data, so that a commonly used well stimulation method can be selected, namely hydraulic fracturing, acidizing, and acid-fracturing.From the ternary diagram plot the XRD (bulk) analysis results show that the distribution of the main minerals (Quartz, Clay, Calcite) is more dominant in the ductile zone, hard to frac category. This shows that all the depth intervals in the OBF-01 and OBF-04 wells are more ductile, and are not recommended for hydraulic fracturing. From the XRD (bulk) analysis, Calcite mineral is more dominant, so for well stimulation work it is recommended to use acidizing or acid-fracturing

Peramalan Kinerja Reservoir Lapangan Panas Bumi Gunung Iyang-Argopuro, Jawa Timur, Indonesia Menggunakan Simulasi Numerik TOUGH2

The Mount Iyang-Argopuro geothermal field is a prospect field located in East Java, Indonesia. This field has a water-dominated reservoir and still in the exploration stage. Therefore, this study was conducted to find out how the production capacity of the Mount Iyang-Argopuro reservoir. The scenario of field development is done by simulating a reservoir model that has reached a natural state. The model was created and simulated with a TOUGH2 simulator, assuming the field will be produced for 30 years with a production capacity of Iyang-Argopuro geothermal field is 55 MW. Several production scenarios are tested on the model to obtain an appropriate production target. Based on the simulation results, a production capacity of 55 MW for 30 years was achieved with 9 production wells. Fluid from the wells flow to a 9 bar pressurized separator and an 8.5 bar turbine pressure. Despite the decline in production, the scenario is still able to maintain generating capacity above 55 MW

Multi Regression Analysis to Suggest Optimum Drilling Weight On Bit and Penetration Rate for Optimum Rate of Penetration Propose Well

R is a system for analyzing statistical data included in open source software group or also called freeware. R software less popular when compared with other paid statistical software such as SPSS, MINITAB, SAS or Eviews. Limited references and support especially in Indonesian, is one of the reasons statistical users prefer commercial statistical packages over free R software and provide results that are no less powerful and interesting graphics systems. Among many statistical techniques that R software can accomplish, one of the most popular is multiple regression analysis. In this article, we will discuss about multiple regression analysis modeling using R software as an alternative software for determining Weight on Bits (WOB) and optimal Rate of Penetration (RPM) in oil and gas drilling. Multi-regression analysis aims to get maximum drilling rate at drilling process, which is reduce drilling time and drilling cost. Bourgoyne and Young ROP models have been chosen to observe effects of several parameters during drilling operations such as drilling depth, pore pressure, equivalent circulation density, bit weight, rotating speed, bit tooth wear and jet collision force were extracted from the final drilling report. Results of the analysis are used to determine the optimum value of the weight of the bit which provides optimal drilling operations and optimized WOB has been calculated for several data points. the results show that R software can be used for multi regression analysis, and and produce a multi-regression equation that can be used to predict the optimum WOB and RPM for further drilling in equivalent rock formations

Natural State Modelling of Salak Geothermal Field

The Awibengkok geothermal field, also known as Salak, is a liquid-dominated field. The commercial Awibengkok reservoir is a moderate-to-high temperature (240–312 ◦C) geothermal resource with high fracture permeability, moderate porosity, and moderate-to-low matrix permeability, and can generate electricity up to 377 MW. This field fracture-controlled reservoir has benign chemistry and low-to-moderate non-condensable gas content. The geothermal reservoir is associated with youngvolcanism and intrusions in a highland area in the west of Salak Mountain and east of the Cianten caldera, a collapsed andesitic stratocone. In this paper, numerical method for calculation is used for modelling and reservoir simulation. A simulator is used to build the model. The model was built until it reached the natural state. The method used for model calibration is through pressure and temperature matching of two wells P-T logging data. One of the well is located on the western region of Salak geothermal field, while the other is located on the eastern region. Salak geothermal field model would reach natural state with simulation time up to millions of years. The model state the field is a liquid-dominated field and has steam caps in western and eastern area. The material on those two areas are different, thus the initial conditions are different. The temperature is higher in the western area. The gas saturation vary between 0.127 to 0.5 and there is a caprock with permeability 9mD