PROCEEDINGS, The 7th Indonesia International Geothermal Convention & Exhibition (IIGCE) 2019

Well targeting is important stage during geothermal development. To plan geothermal well, target is defined based on reservoir boundary and high permeability distribution, which approached by 3D structural and temperature model using Petrel®, a state-of-art and interactive modelling software to design well path while displaying those models.

The objective of this study is to show the workflow of well targeting based on structural and temperature model by using integrated modeling software. All information used for this project is published data from relevant website.

Field X was selected as reference for this project. Located on gently sloping alluvial cover, this field lies inside the margin of sedimentary basin. The regional stratigraphy of this field consists of granitic rocks as basement, and sequence of sedimentary deposits as basin fill. Structurally, four fault systems have been identified with several fracture patterns. High temperature gradient in basement and reservoir rocks 70℃/Km, with maximum temperature 197℃.

Data used for this study are: geological map, lithological intersection, and lineament structure from surface mapping, topography point from geophysical survey, basement depth from gravity survey, alteration, lithological zone, and temperature data from exploration wells.

The workflow utilizes all information start with preparing data, building models of faults, lithology and temperature, then digitizing well for the next target. Data preparation done by collecting all information from website and load them into correct location. Structural model was built as framework for the model, based on topography, basement and lineament data by using structural modeling method. Lithological model was created based on geological map, and intersection information by using geometrical modeling method. Temperature model was defined based on well data by using kriging interpolation method. Geothermal resource then being identified to be used as well target. The result of this study is well plan information based on resource and fault position.