SPE-128742 Urucu Field Integrated Production Model
Sthener R.V. Campos (Petrobras/NTNU) | Alex F. Teixeira (Petrobras) | Leonardo F. Vieira (Petrobras) | Snjezana Sunjerga (PERA A/S)
SPE Intelligent Energy Conference and Exhibition, Utrecht, The Netherlands, 23-25 March 2010
The main objective of this paper is to present a model based integration platform to perform 60+ oil wells optimization in PETROBRAS Urucu field (Solimões Basin, Amazon Rain Forest), while honoring operational constraints on wells, production separators, pipelines, and total field gas processing capacity.
The solution was built based on current technologies of modeling gas and water coning in the high-permeability reservoirs of Urucu, including detailed 3D finite-difference well models automatically history matched to production data, and empirical models based on fundamental flow theory. The well models have been integrated into a prototype solution to simultaneously solve for all 60+ optimal well rate controls. The optimization scheme should determine the optimum setting of well control (e.g. liquid rate) of all the wells in the field and advise on production management of each individual well. The developed concept is presented in the paper.
Another important development presented is a virtual metering modeling that estimates production rate of each well, based on real time data of pressure and temperature measurements on wellhead.
The Urucu field optimization strategy relies intensively on the engineering work related to process and technology. An international and multidisciplinary group including academic collaboration was established to compose the various knowledge needed to embrace the challenge.
1. Urucu Production field
The Urucu field is located in a remote region of primary rainforest 650 km southwest of Manaus in the heartland of the Brazilian Amazon. Petrobras started its production activities in Urucu after the discovery of a significant reserve of oil and natural gas in 1986.
The field consists of three reservoirs called “River Urucu” (RUC), “East of Urucu” (LUC), and “Southeast of Urucu” (SUC). The field has more than 60 production wells and more than 20 injection wells flowing to several manifolds, as depicted in the flowchart in Figure 1. The crude produced in Urucu has average oil gravity of 45 oAPI and GOR ranging from 500 to 5000 m3/m3. Gas expansion is the primary recovery mechanism. Typical field flow rates are 50.000 bpd and 10.5 million Nm³/day of natural gas, with re-injection of 8 million Nm³/day of processed gas as secondary recovery mechanism.
The large range of GOR in the field is due to gas coning behavior. LUC field is the main oil producer and has rate constraint in the gas flowline to LPG “Polo Arara” plant. Therefore, to minimize field GOR is a main subject to maximize oil production.
2. Integrated and Optimization Concepts
Several reservoir and well management techniques to exploit and enhance oil field life cycle have already been discussed in literature, T. Babadagli (2005) gives an extended bibliography on reservoir area. Production fields that already went on primary depletion face secondary/tertiary recovery projects. Infill horizontal drilling is a natural phase of mature field development. The final stage selects an EOR strategy fitted for the specific production scenario.