Melilo Junior, Angelo Celio (Petrobras) | Oliveira da Costa, Carlos Henrique (Petrobras) | Armani Delalibera, Carlos Alberto (Petrobras) | Schwingel Dias, Marco Antônio (Petrobras) | Palmeira de Oliveira, Thomaz Murrieta (Petrobras) | Pereira, Rafael Merenda (Petrobras)
The Libra Extend Well Test (EWT) project is composed of 2 satellite wells interconnected to an FPSO with an external Turret anchor. One well is the producer, with 6-inch service lines and 8-inch production line in lazy wave risers configuration. The other well is the injector, with two 6-inch gas flow lines also in lazy wave compliant configuration. In the project planning several actions were considered in order to guarantee the first oil date determined by the project, while the production unit (FPSO) was not available in the location and ready to pull-in campaign. One of these actions studied and later adopted was the prelaying operation of the flexible lines with floaters in the lazy wave configuration of the production line of the production well. Later on, similar studies were done considering the pre-laying of injection lines also. As this type of operation is not a track records at Petrobras for the ultra-deep water scenario, additional studies were necessary to ensure its feasibility and the safety execution. The objective of this article is to present the previous studies and the result achieved in the pre-laying operation of flexible line with floaters in the lazy wave configuration of the Libra EWT service line.
Fernandes, Andre Alonso (Petrobras) | Vanni, Guilherme Siqueira (Petrobras) | Martinello, Isac Alexandre (Petrobras) | Terra, Felipe de Souza (Petrobras) | Sales, Ivan Mendes (Petrobras) | Guedes, Jonas (Petrobras) | Vasconcelos, Kelliton da Silva (Petrobras)
Manage Pressure Drilling is not a new technology, but the transition from land operation to floaters is still recent. This created a situation where drilling contractors and operators are still learning what the true capabilities of the technology are.
MPD technology adoption on floaters can be divide it in 3 different phases: Use for Early Kick Detection and wellbore stability improvement; Introduction of Hydrostatically Underbalanced fluid; Influx circulation through the MPD system;
Use for Early Kick Detection and wellbore stability improvement;
Introduction of Hydrostatically Underbalanced fluid;
Influx circulation through the MPD system;
In the first phase most of the procedures and barrier concepts stay untouched.
After eliminating initial skepticism, second phase commences. Hydrostatic pressure exerted by the fluid is inferior to the formation pressure. Primary barrier concept alters. The technology can be applied to drill wells with narrow operational windows, unviable conventionally.
Finally, third phase starts with very limited volumes being allowed to be circulated through the MPD system. After first successful influx circulations through the MPD system, increased volumes may be encouraged to be circulated through the primary barrier.
Mendes Sales, Ivan (Petrobras) | Dantas Sitonio guedes, Jonas (Petrobras) | Alexandre Martinello, Isac (Petrobras) | Couto Lemgruber Kropf, Talles (Petrobras) | Mesquita Caetano, Leonardo (Petrobras) | Alonso Fernandes, Andre (Petrobras) | Loures Sa, Lucas (Petrobras)
MPD techniques have being applied to drill zones with major fluid losses or narrow operational window. Nevertheless, subsequent operations are not yet at the same stage of development: Wireline logging, running casing and cementing are still challenging and need further development when it comes to DP rigs. Therefore, after drilling a well with hydrostatically underbalanced fluid and surface backpressure, it is necessary to replace the drilling fluid in order to continue the operations. Although, in nearly all MPD wells it is possible to do this, the major challenges are zones with absent drilling window and severe losses where PMCD technique is required. In these cases, it is not possible to use overbalanced drilling fluid. This paper presents a solution for wireline logging while using MPD techniques on DP rigs with underbalanced drilling fluid. At first, it shows the planning phase and its discussion, then the execution phase with its difficulties.
Aranha, Pedro Esteves (Petrobras) | Colombo, Danilo (Petrobras) | Fernandes, André Alonso (Petrobras) | Vanni, Guilherme Siqueira (Petrobras) | Tomita, Reinaldo Akio (Petrobras) | Lima, Cláudio Benevenuto de Campos (Petrobras) | Lima, Gilson Brito Alves (Federal Fluminense University) | Wasserman, Júlio César de Faria Alvim (Federal Fluminense University)
The demand for ultradeepwater scenarios invoked the frequent application of managed pressure drilling (MPD) in the last few years. In an ultradeepwater scenario, oil companies face issues such as narrow pressure windows and severe loss zones. Many wells are considered undrillable without the aid of MPD technology. MPD operations need to be correctly evaluated with consideration given to increased time and cost/benefit analysis. In this paper, we propose a probabilistic model to evaluate MPD demand by estimating the optimal number of rigs equipped with MPD and a rotating control device (RCD), and we analyze which intervention strategy is the most cost- and time-effective. Reducing uncertainty is an important factor when making decisions about drilling. We adopted a Monte Carlo simulation using loss-zone estimation, probability of prediction error, the number of rigs equipped with MPD, and several strategies. Better MPD strategies were determined on the basis of available data and the optimal number of rigs equipped with an MPD system and RCD equipment, reducing subjectivity in the decision-making process. The originality of our paper lies in the new quantitative approach to dealing with uncertainty in the prediction of fluid losses and the cost and duration of different MPD strategies, numerically simulating the possible scenarios.
Siqueira Vanni, Guilherme (Petrobras) | Alonso Fernandes, André (Petrobras) | Tacio Teixeira, Gleber (Petrobras) | Vieira Martins Lage, Antonio Carlos (Petrobras) | Leibsohn Martins, André (Petrobras) | de Souza Terra, Felipe (Petrobras) | de Souza Cruz, Marcelo (Engineering Simulation and Scientific Software) | Rodrigues G. da Silva, Fabio (Engineering Simulation and Scientific Software) | Édio Dannenhauer, Cristiano (Engineering Simulation and Scientific Software)
Given the complexity related to deepwater drilling with narrow operational windows, any effort to increase the confidence on the safety guidelines should be encouraged. There are many procedures in MPD operations that can be verified and validated during the operations, in order to avoid unforeseen situations.
As initiatives to optimize the drilling process in real time are extremely important, the present study focuses on the development of specific methodologies to support MPD operations, which are implemented on a real time drilling diagnosis software [
It is very useful to review the drilling plan in various situations. With the use of MPD monitoring module is possible to obtain, from the DPPT (Dynamic Pore Pressure Test) and DFIT (Dynamic Formation Integrity Test) procedures, more precise values to compose the operating window. As a consequence of appliying it together with precise hydraulics, cutting transport and torque and drag models, the developed methodology proposes, as output, the ideal operating parameters, such as choke pressure, pump flow rate or adjustments related to the drilling fluid properties. The methodology always considers the best approach to meet the restrictions imposed by the operational window, avoiding drilling problems. Alternatively, if a change on the operating parameters is not sufficient, it also simulates the best position for the Anchor Point.
The developed methodology was successfully applied in a number of MPD wells recently drilled in distinct deepwater locations, in Brazil. The real time optimization procedures proposed in the present paper are a further step to ensure the reliability of MPD operations in challenging scenarios, aiming enhanced efficiency and safety.
Lage, Antonio Carlos Vieira Martins (Petrobras) | Arduino, Edgard Gurgel do Amaral (Petrobras) | Loureiro, Sebastião de Andrade (Petrobras) | Vanni, Guilherme Siqueira (Petrobras) | Filho, Hercilio Pereira da Silva (Petrobras)
The present paper describes performance improvements and well safety achieved with the use of Managed Pressure Drilling (MPD) in the exploratory block of Parva Negra Este, in Neuquén Basin. Petrobras Argentina S.A (PESA), with the technical support from the Petrobras’ headquarters, in Brazil, drilled two exploratory wells applying MPD and targeting Vaca Muerta shale oil & gas play.
High-pressure zones characterized the drilling scenario, reaching, usually, pore pressures higher than 18 lbm/gal in unconventional reservoirs, composed of tight sand and shale. The use of MPD in both well constructions was quite efficient, including well control and plug and abandonment (P&A) operational applications. Those operations proved that MPD can effectively replace the Under-Balanced Drilling (UBD) system, which is standard practice in that area.
In the first well, PESA reported significant gains in drilling performance when compared to other wells previously drilled. Drilling with MPD did not record non-productive time (NPT), differing substantially from the previous wells constructed in the surroundings of Parva Negra Este with an average NPT of 20 days. A considerably larger recovery of coring samples was achieved, being also possible to eliminate one well section, by drilling two zones of interest in a singlesection. Additionally, lessons learned were implemented, resulting on higher rate of penetration (ROP) with the support of MPD.
In the second well, a high overpressurized pore zone was reached, leading to a very complex well control event followed by a permanent P&A operation. The formation pore pressure was much higher than the expected for the area. Instead of using an 18 lbm/gal drilling fluid, it was necessary to weight the fluid up to 21.3 lbm/gal, adding hematite as weighting material. In that scenario, the use of MPD made the operations of circulation and well cementing safer than with the conventional drilling approach utilized in that vicinity.
The application of Dynamic Formation Integrity Tests (DFIT) and Dynamic Pore Pressure Tests (DPPT) ensured a more precise operational window, helping to formulate risk matrices for safely pulling the drilling string out of the hole. In addition, the precise definition of the operational window was a valuable information to plan the best approach for P&A. Besides performing those tests, the MPD system was very useful to evaluate operational parameters and verify how effective was the settlement of the abandonment cement plugs.
In summary, MPD supported safer drilling and P&A jobs, better drilling performance and greater information achievement through more efficient well logging and sample coring.
In this work, we focus on a Bayesian inversion method for the estimation of reservoir properties from seismic data and we study how the inversion parameters, such as rock-physics and geostatistical parameters, can affect the inversion results in terms of reservoir performance quantities (pore volume and connectivity). We apply a Bayesian seismic inversion based on rock-physics prior modeling for the joint estimation of facies, acoustic impedance and porosity. The method is based on a Gibbs algorithm integrated with geostatistical methods that sample spatially correlated subsurface models from the posterior distribution. With the ensemble of multiples scenarios of the subsurface conditioned to the experimental data, we can evaluate two quantities that impact the production of the reservoir: the reservoir connectivity and the connected pore volume. For each set of parameters, the inversion method yields different results. Hence, we perform a sensitivity analysis for the main parameters of the inversion method, in order to understand how the subsurface model may be influenced by erroneous assumptions and parameter settings.
Presentation Date: Monday, October 15, 2018
Start Time: 1:50:00 PM
Location: 206A (Anaheim Convention Center)
Presentation Type: Oral
Marlim R3D is an open-source realistic geoelectric model for CSEM simulations of the post-salt turbiditic reservoirs at the Brazilian offshore margin. In the present article, we report the 3D CSEM finite–difference time domain forward study to generate the full-azimuth CSEM dataset for the MR3D earth model. To that end, we fabricated a survey with 45 towlines striking north-south and east-west directions over a total of 500 receivers evenly spaced at 1 km interval along the rugged seafloor of the MR3D. To accurately represent the thin, disconnected and complex geometries of the studied reservoirs, we have built a finely discretized mesh of 100×100×20 m leading to a large mesh with a total of approximately 90 million cells. We calculated the six electromagnetic field components (Ex, Ey, Ez, Hx, Hy, and Hz) at six frequencies in the 0.125 −1.25 Hz range. A multiplicative noise with a 1% standard deviation was summed to the data. The whole CSEM dataset, with inline and broadside geometries, is being distributed for research or commercial use, under the Creative Common License, at the Zenodo platform.
Presentation Date: Thursday, October 18, 2018
Start Time: 8:30:00 AM
Location: 213A (Anaheim Convention Center)
Presentation Type: Oral
Maul, Alexandre (Petrobras) | Fonseca, Josué (Petrobras) | Teixeira, Leonardo (Petrobras) | Barros, Pablo (Petrobras) | Boechat, João (Petrobras) | Nunes, João Paulo (Petrobras) | Yamamoto, Thiago (Petrobras) | González, María (Emerson-Paradigm) | González, Gerardo (Emerson-Paradigm)
Meneguim, T., S. C. Mendes, A. Maul, L. Falcão, M. González, and G. González, 2015, Combining seismic facies analysis and well information to guide new interval velocity models for a pre-salt study, Santos Basin, Brazil (14th International Congress of the Brazilian Geophysical Society), Rio de Janeiro, RJ, Brazil, https://doi.org/10.1190/sbgf2015-271. Teixeira, L., F. Gobatto, A. Maul, N. Cruz, C. Gonçalves, and J. Laquini, 2017, Rock physics and seismic inversion to identify stratification within salt section supporting velocity, facies modeling and geomechanical analysis (15th International Congress of the Brazilian Geophysical Society), Rio de Janeiro, RJ, Brazil, https://doi.org/10.1190/sbgf2017-002.
Penna, Rodrigo (Petrobras) | Araújo, Sergio (Petrobras) | Sansonowski, Rui (Petrobras) | Oliveira, Leonardo (Petrobras) | Rosseto, João (Petrobras) | Geisslinger, Axel (Shell) | Matos, Marcilio (SISMO)
The recent discoveries made in the pre-Salt carbonates, southeast Brazil, are among the World’s most important ones in the past decade. This province, especially Santos Basin, comprises large accumulations of excellent quality and high commercial value oil.
The latest seismic processing technologies along with Elastic Inversion have been used for reservoir characterization and in particular identifying carbonates with high-permeability intervals to model flow behavior of the reservoirs. One challenge encountered, however is identifying the occurrence of igneous bodies within the reservoir interval and their correct characterization as input into the reservoir modelling, once they may act as flow barriers or even high-permeability corridors, if fracturing is high enough.
Presentation Date: Wednesday, October 17, 2018
Start Time: 1:50:00 PM
Location: 209A (Anaheim Convention Center)
Presentation Type: Oral