Real Time Petrophysical Data Analysis for Well Completions Installed in Oil Fields in the Amazon Basin in Ecuador Ivan Vela, Oscar Morales and Fabricio Sierra, Petroamazonas, Ecuador, and Francisco Porturas, Halliburton, Brasil. Copyright 2013, SBGf - S ociedade Brasileira de Geofísica its interpretation is a unique source of information of rock and fluid properties for a final calibration of predicted This paper was prepared f or presentati on during the 13th I nternational Congress of the Brazilian G eophysical S ociet y held in Rio de Janeiro, Brazil, A ugust 26-29, 2013. m odels , base cas es as an aid to install an efficient completion hardware. Contents of this paper were reviewed by the T echnic al Committee of the 13th International Congress of the Brazilian G eophysical Soci et y and do not nec essaril y represent any position of the SBG f, its officers or members. Electronic reproduction or Depending on the well geometry, wells are com pleted storage of any part of this paper f or commercial purpos es without the written consent of the Brazilian G eophysical Soci et y is pr ohibit ed. with a variety of completion equipment, from conventional ____________________________________________________________________________ slotted liners, to standalone screens (SAS) and only Abstract recently with ICDs and Autonomous Inflow Control Devices (AICDs) and or Interval Control Valves (ICVs), Petrophysical interpretation of Logging While Drilling usually incorporating some level of compartmentalization (LWD) data, acquired real time or later downloaded and zonal isolation with swellable packers. from memory data, is applied to estimate valuable reservoir rock and fluid properties. Permeability is LWD logs are retrieved either from real time data or from derived from porosity while fluid saturations from memory data. After data quality control, it is followed by a resistivity logs. Petrophysical interpretation output quick look petrophysical evaluation which often is depends on log data quality control, local area geo- performed simultaneously with ongoing drilling reservoir-knowledge and understanding of tool operations. This process is very fast, because the lim ited physical principles. This is of paramount importance tim e between the drill b i ts reaches Total Depth (TD) until when core data is not available, and then core installation of the final completion architecture. calibration is absent. Petrophysical data interpretation results are the Rock properties such as permeability are extracted from most valuable input for updating any base case inversion of porosity logs while the fluid saturations are completion scenarios, for last calibration and from resistivity logs (duly corrected for salinity effects). refinement of the completion hardware design, prior There is no standard methodology to extract these to its installation in the ground. It is recommended to parameters, therefore quality control, local area include several sensitivities and scenarios to assess knowledge and tool principles are a must. This is well completion performance dynamic ranges in particularly important when core data is not available, and terms of fluid rates, water cut and available then core calibration is absent. drawdown pressures. Preparation of cross-plots, standard deviation flags and petrophysical attributes The completion refinement should include and sense are all integrated to minimize risk and uncertainties several and multiple scenarios to predict well related to both reservoir rock and fluid properties. performance dynamic ranges and thus minimizing Both LWD data quality control and petrophysical uncertainties related to both rock and fluid properties. interpretations are often performed parallel and or Ge o-Reservoir Challenges simultaneously to ongoing drilling operations. Often, time is short between the drill bit reaches TD to the Geologically the Oriente Basin is part of the Upper installation of the completion hardware. Amazon River drainage system and covers an area of This paper presents the methodology, workflow and approximately 80,000 km2 which is very prolific for oil and only a couple of field examples of successful gas production. It is geologically continuous with the petrophysical-completion s ynergism in recent w e ll Putumayo basin in Colombia and the Marañon basin in completions installed with ICDs and AICDs in oil Peru, separated only by geological arches located north producer wells in Ecuador Amazon Basin. and south east of the basin. Figure 1 shows the Bloque 15 location and a generalized stratigraphy with related Introduction reservoirs. Currently, all drilled wells include Measurements While The main reservoirs are in clastic rocks, both Drilling (MWD) and Logging While Drilling (LWD) real time consolidated and non-consolidated s ands tones and log data acquisition independently if a well is drilled for exhibiting a wide range of reservoir fluid and rock exploration, appraisal, delineation, production or injection. properties. Fluids API degrees and vis cos ity often varies Acquired real time data is a valuable input for a sound areal from 4 cP, 6 cP, 8 cP, 12 cP, 22 cP, 47 cP, 67 cP, petrophysical evaluation of reservoir targets and of 110 cP , 140 cP, and greater than 240 cP. paramount importance for designing any completion type solution to produce or inject fluids. Besides log data and Thirteenth International Congress of the Brazilian Geophysical Society REAL TIME PETROPHYSICS DATA ANALYSIS FOR WELL COMPLETIONS IN ECUADOR ______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________2 Initially, the Oriente Basin oil fields were producing from A Recent Type of Well Completion Hardware installed low deviated wells and were completed conventionally in Ecuador (mostly slotted liners), often resulting in a) an uneven reservoir influx, b) without pressure adjustment, c) non- Well completions hardware has evolved from uniform an selective reservoir drainage, d) strong and conventional slotted liners to a variety of Inflow Control early water coning, e) well interferences and f) non- Devices (ICD), mostly acting passively downhole to optimal area sweep and leaving compartments of by- Interval Control Valves (ICV) components of intelligent passed oil. Other wells were completed with dual s tring and smart wells which allow for an active reservoir solutions to produce from two zones simultaneously but monitoring. Figure 3 show the Autonomous Inflow still affected by early coning. Control Devices (AICDs) installed to minimize Heel-Toe effects, delay early well coning, balancing flux, adjusting Figure 2 shows a visualization of associated reservoir pressure and lowering water cut, along the entire challenges. wellbore, thus allowing for well production longevity, an efficient reservoir drainage and area sweep. Methodology Examples: Well completion cases A priori, an initial completion case model and scenario is prepared, which is based on proposed well trajectory and The AICD completion option was chosen, to restrict the well offset geo-reservoir data. Later, during drilling, geo- production of water and delay and early breakthrough to control and navigation data is integrated. Here, L WD minimize water cut. availability and its sound petrophysical evaluation and interpretation is added into the initial base case and Figures 4 shows permeability and fluid saturation profiles refined and calibrated with field all available data interpreted from LWD data, used to refine the final AICD measurements. Then, the completion is refined and or completion (Well 1). totally modified depending on reservoir rock and fluid properties obtained from petrophysical interpretation of Figure 5 shows the integration from petrophysical LWD data and or wire line logs. interpretation results through flux responses of the final AICD completion (Well 2). A workflow is developed for a synergetic and cross- fertilized interrogation all available data and operational risk minimization and among the Operator Asset Team Summary and Service company, including: The petrophys ical-completion integrated methodology 1. Holistic view and follow up of well prognosis, and workflow is successfully applied in Ecuador oil wells and this type of analysis and approaches has been geo-navigation and landing. extended to other completions types or com pletion 2. Insight of LWD real time logs, anywhere and solutions in the area. composite visualizations of GR, Resistivity, Porosity and Neutron logs, together with References navigation and prognosis to TD of the well. 3. Preparing a preliminary well completion proposal Davila, E., Almeida, R., Vela, I., Pazos, J., Coello, K., and mechanical state of the well. Chinellato, F., Humbert, O. and Porturas, F. [2009] Fi rs t Applications of Inflow Control Devices (ICD) in Open Hole 4. Evaluation of completion alternatives, based on Horizontal Wells in Block 15, Ecuador, SPE123008, parallel pretrophysical evaluation results. LACPEC, Cartagena, Colombia, 31 May-3 June. 5. Sens ing expected fluid rates, available drawdown pressure and cumulative oil Acknowledgements completion responses. 6. Refining and calibrating the final completion We want to acknowledge Petroamazonas Asset Team, ready for installation: the completion option that Ecuador, for