Precisely Production Forecast After Conducting Hydraulic Fracturing Using Water Cut And Ratio Cumulative Production - Total Water Injected Trend

Abstract

Alfa Structure was established at 1982 and performed 2 drilling wells. There is only one well that have been producing since 1982 to present with 30 bopd and cumulative 429 MSTB. This well produce with tank on site due to the distance with existing location. This structure has not been developed for a long time, therefore in 2019 a seismic 3D survey was conducted. Subsurface opportunity appearance from this study.

At least 7 wells plan were planned to be drilled to develop this structure. Main reservoir is Upper TAF with low resistivity and low quality reservoir therefore Hydraulic fracturing is a one of the proper methods to produce the well from Alfa Reservoir. More than 1000 bopd from 5 wells that has been drilled in 2021 and 2022 with using Hydraulic Fracturing method. Considering subsurface uncertainty to develop surface facilities, production forecast become essential especially in oil forecast. To monitor performance and forecast oil production after conducting Hydraulic Fracturing, this paper aims to share valuable field experience between Water Cut and comparation cumulative production - total water injected.

Alfa Structure produced only 30 bopd previously, but currently become more than 1000 bopd after developing 5 wells infill drilling with using hydraulic fracturing. Every Infill drilling that is carried out by hydraulic fracturing at the beginning of the start-up of well production, the fluid that comes out is water that we inject into the reservoir when doing hydraulic fracturing. Total water injected comes from Breakdown test, Multi rate test, calibration test and Main fracturing. By the time production, water will
decrease and oil comes up with following Water Cut and comparation cumulative production - total water injected trend. As the result, The existence of this trend will be a reference in every monitoring of well production after using hydraulic fracturing and with that we can estimate more precisely when the well will produce according to its potential and very useful in surface facilities planning.