Production and drilling activities in offshore installation are one of the most necessary activities of human society. To drill a subsea well and raise the crude oil to a platform, by itself, presents a series of risks. Associated with this activity, when the crude oil reaches the topside of the platform, there are a number of operations that prepare the oil and gas to be exported to land by pipelines or oil tanker vessels, which involves equipment and process that take high temperatures, high pressure and high flow rates. Understanding the dynamics of the factors that can affect the interaction of operators with all these offshore complex systems is critical, because the loss of control of these systems can cause serious accidents, resulting in injuries to workers, environmental damage, loss of production and geopolitical crises. Accidents in the oil and gas offshore installations, such as drilling rigs and FPSOs, can have tragic consequences and all efforts should be targeted to prevent its recurrence. Therefore, from the perspective of current technological developments, it is essential to consider the influence of Human Factors in the risk management of offshore industrial plants.
Africa (Sub-Sahara) Vaalco Energy started oil production from the Etame 12-H development well offshore Gabon. The well was drilled to a measured depth of approximately 3450 m and was targeting the recently discovered lower lobe of the Gamba reservoir. It was brought on line at a rate of 2,000 BOPD with no indication of hydrogen sulfide. Vaalco (28.07%) is the operator with partners Addax Petroleum (31.63%), Sasol (27.75%), Asia Pacific KrisEnergy started drilling the Rossukon-2 exploration well on Block G6/48 in the Gulf of Thailand, using the Key Gibraltar jackup rig. The well will reach a total depth at 5,462 ft and will test Early Miocene stacked fluvial sandstones on a broad structural high. The well will also appraise the Rossukon-1 reservoir, which produced 850 BOPD during tests.
Subsea Production Systems—Will 2019 Be a Tipping Point? The Golfinho gas field development is among the high-profile projects for which operators agreed to EPC contracts prior to FID. The 286 subsea trees ordered in 2018 was the highest quantity since 2013 and suggests an industry firmly on the right side of a recovery. Increasing orders are a welcome relief for the still-beleaguered subsea supply chain but have yet to translate into meaningful revenue growth. Revenues have remained relatively static over the past 24 months as the growing number of subsea projects hitting the EPCI phase is offset by a transition from high-value pre-2014 backlog to much lower- priced post-downturn contracts.
For more than 50 years, coiled tubing (CT) has been an intervention technology used primarily to maintain or increase production. In the last 10 years, CT telemetry systems have been used for such applications as milling, stimulation, well cleanouts, gas lifting, camera services, logging, and perforating. These systems have resulted in increased certainty, improved safety and efficiency, and reduced time and cost. In this article, a review of a CT telemetry system with 0.125-in. tube wire, including the technology development and field applications, is presented for the first time. Unlike conventional CT for which surface-measured parameters, such as CT weight and length and pumping pressure, are the only parameters available to monitor the operation’s progress, CT telemetry systems provide real-time monitoring of downhole data such as pressure, temperature, depth, and others. The CT telemetry system described in this article consists of the surface hardware and software, a 0.125-in. tube wire inside the CT connecting the surface equipment and the downhole tools and sensors, and a versatile bottomhole assembly (BHA), designed in three sizes (i.e., 2.125-, 2.875-, and 3.5-in.). The 0.125-in. tube wire has the dual purpose of powering the downhole sensors and transferring the real-time downhole data to the surface. The sensors available are a casing-collar locator (CCL), two pressure and temperature transducers (capable of measuring downhole data inside and outside the BHA), and tension, compression, and torque gauges. In addition, cameras with front and lateral views and flow-through capabilities could be used. One of the advantages of this CT telemetry system is its versatility: Switching between applications is as simple as changing parts of the BHA, significantly reducing the operational time and cost, and increasing safety. Another advantage stems from the acquisition of real-time downhole data, enabling the CT field crew to intervene promptly on the basis of dynamic downhole events. A state-of-the-technology review of the 0.125-in. tube-wire CT telemetry system is presented for the first time. The many benefits of the real-time monitoring of the downhole parameters during such CT applications are summarized. These applications include logging, zonal isolation, collapsed-casing identification, scale removal, cleanout and perforation, milling, confirmation of jar activation during fishing jobs, and others. Many of these applications were performed together, and the real-time monitoring of downhole data increased the job efficiency, control, and safety, and reduced the operational costs by simplifying the operational procedures and equipment.
Several actions have been implemented to strengthen process safety and improve safety culture involving Petrobras' E&P activities in the Campos Basin - Brazil, such as Process Safety Program, Strategic Project Excellence in HSE, Evaluation of HSE Management, improvement of standards and procedures, creation of HSE Management Manual and E&P Safety Manual, among others. Additionally, at regulatory sphere, new operational safety regulations were established by the Brazilian National Petroleum, Gas and Biofuels Agency (ANP; most acronyms derived from respective Portuguese expressions, throughout this paper), such as the Operational Safety Management System, Technical Regulation of the Subsea Systems Operational Safety Management System and Well Integrity Management System. More than 400 million men-hour exposed to risk were employed on Petrobras offshore production facilities operations (owned and contractors, except drilling and logistics) in Campos Basin between 2010 and 2017. This number represents an increase of 43% when compared to previous decade, but the rate of time-lost injuries and recordable incidents decreased about 20% in the same period. All actions allowed a significant reduction in number of casualties in Petrobras offshore facilities operations - 01 casualty in the period. Many other actions were deployed at drilling and logistics operations, also helping to achieve the reduction of accidents goals. Aviation's Safety Case, for instance, involves several actions, from helicopters' companies, passing by airports, up to helidecks and offshore crew. This work presents the main implemented programs and actions, as well as the challenges to comply with the various applicable laws, and the search for the zero accident objective in oil and gas production activities in the Campos Basin.
The SPE Distinguished Lecturer Program is funded principally through a grant from the SPE Foundation. The society gratefully acknowledges the companies that support this program by allowing their professionals to participate as lecturers. Horizontal Section: 380m 8 ½" Well; 5 ½" 250 µ screen Proppant: 16/20 mesh (Ceramic) Frac gradient 0.60 psi/ft Smaller screen diameter - 3 ½" Injection of high fluid volumes - calibration tests and fracpack (minimum 10000 bbl estimated) Longer rig time to flow back the well and environmental restrictions (zero discharge). No guns and rig time No fluid injection and related problems with flow back, separation, environmental restrictions. The evaluation is fast; OHGP with low pump rate and pressure, low power, no gel, lower costs and risks.
Bruhn, Carlos H. L. (Petrobras E&P) | Pinto, Antonio C. C. (Petrobras E&P) | Johann, Paulo R. S. (Petrobras E&P) | Branco, Celso C. M. (Petrobras E&P) | Salomão, Marcelo C. (Petrobras E&P) | Freire, Ednilson B. (Petrobras E&P)
Petrobras found almost 100 hydrocarbon accumulations in the Campos and Santos basins, between 50 and 300 km off the Brazilian coast (under water depths from 80 to 2,400 m), which produce from very different types of reservoirs, including mostly (1) pre-salt coquinas and microbialites, (2) post-salt calcarenites, and (3) post-salt siliciclastic turbidites. These different types of reservoirs, containing also different types of hydrocarbons and contaminants provided many challenges for their production development, related to distinct tools and workflows for reservoir (static/dynamic) characterization and management, seismic reservoir characterization and monitoring, recovery methods (water injection, WAG, etc.), well spacing, well types and geometries, subsea systems, and processing capacity of production units.
Since the first oil and gas discoveries in the Campos (1974) and Santos (1979) basins, Petrobras continuously moved to aggressive exploration and production from shallow- to deep- and ultra-deep waters. During the last 40 years, the activities of reservoir characterization and management have also continuously evolved. Four major phases can be depicted: (1) shallow water fields developed with a large number of vertical or deviated wells (e.g. Namorado, and Pampo, Campos Basin); (2) deep water fields, still developed with a large number of wells, but now combining vertical/deviated and horizontal wells (e.g. Marlim and Albacora, Campos Basin); (3) deep to ultra-deep water, post-salt fields, containing light to heavy oil (13-31 °API) in siliciclastic turbidites and carbonates, developed with a relatively small number of mostly horizontal wells (e.g. Marlim Sul, and Barracuda, Campos Basin); (4) ultra-deep water, pre-salt fields with very thick (up to 400-500 m), light oil (27-30 °API) carbonate reservoirs, developed with largely-spaced vertical and deviated wells (e.g. Lula, and Buzios, Santos Basin).
de Oliveira, R. Caldeira (PETROBRAS S.A.) | Gasparetto, V. (PETROBRAS S.A.) | Oazen, E. V. (PETROBRAS S.A.) | Senra, S. F. (PETROBRAS S.A.) | Aguiar, L. L. (PETROBRAS S.A.) | Valença, C. J. (PETROBRAS S.A.) | Lima, D. L. (PETROBRAS S.A.) | Carrara, W. (PETROBRAS S.A.) | Lemos, C. A. D. (PETROBRAS S.A.)
This paper aims to describe developments in the Santos Basin Pre-Salt risers systems, which in some few years experienced many different concepts to overcome big challenges. This paper also describes initiatives to optimize configurations with evolution and maturity of riser technologies and expectations for future developments.
In Santos basin Pre-Salt cluster, due to the challenging environmental conditions, presence of H2S and CO2, water depth up to 2310m, production riser's insulation requirements, relatively high temperature and high pressure, the riser system design for this scenario was something innovative and challenging for the industry. Currently, due to lower oil prices, an even more complex scenario is in evidence, imposing even greater challenges for risers systems regarding cost reduction. The experience acquired with the implementation of the first projects was a key factor to find viable and comprehensive ways to optimize cost.
In approximately 7 years of production in the Santos basin Pre-Salt layer, oil production surpassed 1 million bpd by using several different riser concepts: BSRs (Buoy-Supported Risers), SLWRs (Steel Lazy Wave Risers), Flexible Lazy Wave Risers, Free Hanging Flexible Risers and FSHRs (Free Standing Hybrid Risers). Nowadays, with greater maturity and new design premises, considerable cost reduction results have been obtained, mainly motivated by the reduction of buoyancy modules and reduction of riser sections quantity in the flexible risers. For the future, there are other ongoing optimizations studies to apply both flexible and rigid risers in free hanging configuration.
In early stages of project development, an extensive engineering work on riser analysis, the establishment of new design premise and some changes on current design process were done through a joint effort by operator, partners and suppliers. These are key factors for the achievement of considerable cost reduction. The maturity reached with the riser system designs was obtained through several design cycles, whose process can bring more future cost reductions.
For more than 50 years, coiled tubing (CT) has been an intervention technology primarily used to maintain or increase production. In the last 10 years, CT telemetry systems have been used for such applications as milling, stimulation, well cleanouts, gas lifting, camera services, logging and perforating, increasing certainty, improving safety and efficiency, and reducing time and cost. In this paper, a review of a CT telemetry system with 2 ⅛-in. tube wire, including the technology development and field application, is presented for the first time.
Unlike conventional CT for which surface-measured parameters, such as CT weight and length and pumping pressure, are the only parameters available to monitor the operation's progress, CT telemetry systems provide real-time monitoring of downhole data such as pressure, temperature, depth, etc. The CT telemetry system described in this paper consists of the surface hardware and software, a 2 ⅛-in. tube wire inside the CT connecting the surface equipment and the downhole tools and sensors, and a versatile bottomhole assembly, designed in three sizes (i.e., 2 ⅛-, 2 ⅞-, and 3 ½-in.). The 2 ⅛-in. tube wire has the dual purpose to power up the downhole sensors and to transfer the real-time downhole data to surface. The sensors available are a casing collar locator (CCL), two pressure and temperature transducers (capable to measure downhole data inside and outside of the tool), and tension, compression, and torque gauges. In addition, cameras with front and lateral views and flow-through capabilities could be used. One of the advantages of this CT telemetry system is its versatility: switching between applications is as simple as only changing parts of the bottomhole assembly, significantly reducing the operational time and cost and increasing safety. Another advantage stems from the downhole data certainty in real time, as the CT field crew can promptly intervene based on dynamic downhole events.
A state-of-the-technology review of the 2 ⅛-in. tube wire CT telemetry system is presented for the first time. The many benefits of the real-time monitoring of the downhole parameters during such CT applications as logging, zonal isolation, collapsed casing identification, scale removal, cleanout and perforation, milling, confirmation of jar activation during fishing jobs, etc., are also summarized. Many of these applications were performed together and the real-time monitoring of downhole data increased the job efficiency, control and safety and reduced the operational costs by simplifying the operational procedures and equipment.
The paper summarizes the results stemming from 10 years of global experience with the 2 ⅛-in. tube wire CT telemetry system. A new case history involving the 2 ⅛-in. tube wire CT telemetry system and a vibratory tool is presented for the first time. As currently there is a strong inertia to automate the drilling operations, all details presented in this paper show that the CT telemetry systems are poised to become standard technologies for all CT operations in the not-so-distant future.
Least-squares migration (LSM) attempts to obtain an estimate of the earth's reflectivity by inverting the propagation of waves. It goes beyond standard imaging, which uses the adjoint of the modeling operator only. Therefore, it promises to compensate for illumination variations due to both acquisition geometry and complex overburden. We present the application of an image-domain single-iteration least-squares RTM (LSRTM) approach to narrow-azimuth streamer data from two basins offshore Brazil: the Santos and Espírito Santo basins. We show that such imaging can improve the amplitudes of images below a complex overburden and reduce migration artifacts when compared to standard RTM. Moreover, we validate the effectiveness of the method by calculating point-spread functions (PSFs) after LSRTM and comparing them to PSFs after standard RTM in terms of amplitude balancing and focusing of the PSFs. We show that comparison of the PSFs resulting from both methods provides a robust approach to quality control the LSRTM results in terms of correcting for illumination variations.
Presentation Date: Wednesday, September 27, 2017
Start Time: 10:35 AM
Presentation Type: ORAL