b'Engineer Innovation | Plant & ProcessPhase IPhase IIPhase IIVolumePhase IDewatering of well and gasGas production build-upPhase IIPeek Gas ProductionPhase II Gas Production decline and long term water productionWaterTimeFigure 1: CSG well production phases - Source: Capital Energy Group 2014coming in will now be able to escapesystem. Pipe sections have been from the bend. In this scenario gaugehighlighted in red where disrupted pressure, p1 will be equal to gaugegravity flow is expected to occur. The pressure, p0 plus the static elevation,total physical extension of the below HSTA.gathering system is about 8km x 8km.As can be seen from the below model inThe geometry of a water gathering figure 4, the pressures in gas filledsystem is usually described in shape files downhill sections will be accumulative asgenerated by geographic information the downstream gas bubble will need tosystem (GIS) software. Simcenter be pushed by the upstream gas bubbleFlomaster software enables the import to overcome the water column in cup 2.of complete shape files containing the This cascading effect will feed pressurecoordinates of individual pipeline back to HPV1 and therefore defines thesections as well as their length and backpressure the PC pump has todiameter. Such import functionality is overcome in order to maintain itsvery time efficient and enables the pumping rate.creation of a complex and realistic hydraulic model in a short time period. Modeling of downhill water gatheringPC pump performance curves have to be systemsadded manually at each wellhead to Shown in figure 5 is the schematic of acomplete the hydraulic model.typical small downhill water gathering Shown below in figure 6 is the Simcenter Flomaster hydraulic model of the above typical downhill water gathering system HPV 1 IN OPERATION which was created automatically from the geometry of the imported GIS shape file. Disrupted gravity flow functionally GRAVITY SECTION 1 GAS FILLED (HPVs out of service) was added to the WELL HEAD HPV 2 IN OPERATION model and is further described below. GRAVITY SECTION 2PC pump performance curves shown in GAS FILLED TANK figure 7 have been added to the above hydraulic model which are the main variables during the simulation process. This typical water gathering system contains some high and several low water producing wells. While the majority of wells will start up early, the last well, Figure 2: Downhill pipeline schematicHPVs working correctlyWH14, comes on line some 311 days after 50'