| Title | AN APPLICATION OF 3D TEMPERATURE MODELING DURING AND AFTER DEVELOPMENT DRILLING AT MUARA LABOH, SUMATERA, INDONESIA |
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| Authors | D.A. Dyaksa, J. Stimac, M. Baroek, M. Sihotang, I. Ramadhan, R. Martikno |
| Year | 2018 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | 3D geothermal modeling, temperature model, Muara Laboh |
| Abstract | 3D temperature models were constructed utilizing static well temperature data to better understand the thermal anomaly and likely reservoir extent of the Muara Laboh field. Model iterations were built and updated during and after development drilling in 2017-2018. The 3D temperature models were developed using Leapfrog Geothermal© software. Multi-disciplinary datasets were selected and incorporated to provide constraints on the likely temperature distribution away from wells. Considering the complexity of the horizontal and vertical temperature distribution in the field and limited well data, instead of using conventional 2D temperature cross sections, a horizontal slicing method was used to construct the 3D temperature model at various elevations from the top of reservoir (TOR) at 800 m asl to the deepest well data at -1300 m asl. Temperature was hand-contoured at specific elevations utilizing the well data. Away from wells, temperature was inferred from structural boundaries and low resistivity (value <5 ohm-m) as indicated from 3D magnetotelluric modeling. Thickening and draping of the conductor limited the probable reservoir extent in some areas. The hand-contoured temperature polylines were used as an input to build and interpolate 3D temperature bodies in Leapfrog. From review of well permeability, lithology, and vein mineralogy, it was found that some parts of the high temperature body had low permeability, and that deep high permeability was associated with dike intrusions in the SW. These factors were considered along with temperature when the model was used for well targeting and planning as the 11-well development program progressed. Learnings about permeability were used to construct reservoir bodies where both high temperature and permeability were most likely to exist. The 3D temperature model was updated after drilling, enhanced by new information from geology to better portray the permeability character in Muara Laboh. This 3D model was one of the key inputs in updating the Muara Laboh conceptual model and numerical models. |