On-Demand Simulation of Energy and Chemistry Balance of the 700 MW Greater Tongonan Geothermal Field

Abstract

Management of voluminous physical and chemical data generated from the operation of the Greater Tongonan Geothermal Fluid Collection and Reinjection System (FCRS) was automated for efficiency in data extraction and usage. The program (ISIM) uses spreadsheet software as a client tool in automating data extraction for simulation of energy and chemistry balances in the pipeline network. It manages on-demand calculation of steam capability and supply to the 5 main power plants and 4 optimization plants, including chemistry simulations of non-condensable gas (NCG) levels in steam supply and brine silica saturation indices (SSI). The spreadsheet integrates VBA programming for the automated data extraction from ORACLE database system and performs geochemical data reduction and separation calculations from production well water and gas chemistry, well discharge flowrates and enthalpies, and sampling and pipeline conditions.

The program captures data from 5 FCRS and power plants in GTGF. The geothermal fluids are separated in 4 different type of geothermal power systems, namely: (1) single-flash geothermal combined cycle unit (GCCU) in Upper Mahiao; (2) double-flash conventional power plant with Topping Cycle in Tongonan-1 and Mahanagdong-A; (3) double-flash conventional power plant with Bottoming Cycle in Malitbog-South Sambaloran; and (4) single-flash conventional power plant with Topping Cycle in Mahanagdong-B. All these 5 FCRS and 4 Power Systems are interconnected into one of the biggest geothermal pipeline network in the world through the Steamline Interconnection Stages 1, 2 and 3, otherwise known as the ôSteam Highwayö. This in effect integrates the energy and chemistry balances from 79 production wells and 38 reinjection lines and wells.