Ultra-deep Water Research Articles

Probabilistic Neural Network with Bayesian-based, spectral torque imaging and Deep Convolutional Autoencoder for PDC bit wear monitoring

Drill bit wear monitoring plays an important role during drilling operations, particularly in drilling challenging environments, such as ultradeep water and hard rock formations. The machine learning algorithms, applied to real-time analysis, has occupied an important role in the oil well industry. We here propose a machine learning system to aid drill bit wear assessment for real-time operations, using a Probabilistic Neural Network (PNN) and Bayes Theorem, combined with Power Spectral Density (PSD) of surface torque image and feature extraction by Deep Convolutional Autoencoder (DCAE). A case study was performed with wells from Brazilian ultradeep water pre-salt fields. The analysis shows that a feature extraction DCAE is more efficient to discriminate the bit wear state when compared with PSD torque image and torque raw data. After that, several numerical experiments were performed to investigate the best machine learning classification model, considering DCAE feature extraction. The cross-validation results considering all the dataset shows the PNN evaluation metrics: 87% accuracy, 83% precision, 91% recall and 86% for F1-score. The field tests validation was performed in real-time simulation, with 3 wells from the original dataset plus 2 offset wells. The simulations show that the proposed system can capture the best moment for the tripping pipe to replace a worn-out drill bit. The field tests experimental results indicate that the system proposed can aid drilling engineers in monitoring Polycrystalline Diamond Compact (PDC) drill bit wear in real-time operations.

Rheology of methane hydrate slurries formed from water-in-oil emulsion with different surfactants concentrations

As oil and gas production moves into ultra-deep water, hydrate blockage has been a major flow assurance issue. Transport in the form of flowing hydrate slurry is an effective method to prevent hydrate blockage with an addition of surfactants. To determine the impact of surfactants on rheological behavior of hydrate slurry, the high-pressure rheological experiment was conducted on methane hydrate slurry formed from emulsion with 50 vol% water cut but different surfactants concentrations. The emulsions were prepared with deionized water, n-decane and two non-ionic surfactants (Span 80 as an anti-agglomerant and Tween 80 as a co-surfactant). The experimental results indicate that a lower surfactants concentration would greatly accelerate hydrate formation, causing blockage in a shorter time. While the higher the surfactants concentration, the more stable the slurry when hydrate formation. As the surfactant concentration was over 5 wt% in the oil phase, slurry viscosity decreased significantly, and hydrate slurry showed a good flow performance. Furthermore, a simulation of shut-in and restart was conducted after slurry reaching a steady-state. It was found that during the first 10 min of shut-in process, yield stress at restart was basically unchanged, while when the shut-in time exceeded 20 min, the yield stress increased significantly with the increase of the shut-in time, and an increase of surfactants concentration would have a negative effect on this trend. As the surfactant concentration was over 5 wt%, the flow performance of hydrate slurry remained good after 1280 min shut-in and restart, with little change in rheological behavior.

Intelligent Completion Installations Instrumental in Brazilian Presalt Development

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 195935, “Hundredth Intelligent Completion Installation: A Milestone in Brazilian Presalt Development,” by Eduardo Schnitzler, SPE, Luciano Ferreira Gonçalez, and Roger Savoldi Roman, Petrobras, et al., prepared for the 2019 SPE Annual Technical Conference and Exhibition, Calgary, 30 September–2 October. The paper has not been peer reviewed. Presalt heterogeneous carbonate reservoirs typically present long net pays, high production and injection rates, and flow-assurance risks. The complete paper presents a discussion of the use of intelligent well completion (IWC) in Santos Basin Presalt Cluster (SBPSC) wells. With the use of this technique and the introduction of several improvements, well-completion time was reduced to less than 50% of that seen in initial wells. Introduction The SBPSC is in ultradeep water—be-tween 1900 and 2400 m—approximately 290 km offshore Rio de Janeiro. From the opening phases of SBPSC development, IWC has been crucial, not only to improve reservoir management but also to provide better capability to deal with reservoir uncertainty. Extensive use of IWC has presented challenges for well-engineering teams because of the complexity associated with this completion design. Minimizing well-construction costs and risks is essential for any project, but, in ultradeep water, it is even more critical. Intelligent Completion Systems Internal risk assessments were conducted to determine optimal solutions for the first production-development project. Direct hydraulic systems were chosen to actuate interval control valves (ICVs) remotely in two- and three-zone wells. This field-proven system was considered the simplest and most reliable for long-term use. However, because the wet tree (WT) designed for SBPSC projects comprises multiplex control systems, addressing these additional integration issues during the planning phase demands exceptional efforts. An extensive integration process had to be conducted to assure that every interface would perform correctly during the production phase. Most projects consider the use of a 95/8- or 97/8-in. production casing set and cemented in front of the reservoir, allowing the use of wider completion equipment, including IWC components. The use of larger-diameter accessories provides the production string the capability to deal with higher mechanical loads, a feature important in the absence of an expansion joint. The full completion string, installed in a single run, has no separated lower completion system. This integral completion design avoids the use of down-hole connections and allows control lines to be run continuously during deployment and the equipment functionality to be tested fully during installation. Dedicated pressure and temperature sensors are located on each interval and inside the completion string. For two-zone production wells, three chemical-injection points are available. Two of them are upstream of the ICVs to prevent scaling formation in the valves by injecting scale inhibitors in the annulus. These chemical-injection points are especially important when producing the well with any of the ICVs in choked positions, leading to higher-pressure drops across the valves. A third chemical-injection system, injecting into the production string, is above the upper packer and may be used for a second chemical injection or as a backup for the main chemical-injection systems.

FEM-based evaluation of friction and initial imperfections effects on sandwich pipes local buckling

Sandwich pipes have been studied as one option to overcome the high pressure problems in deep and ultra-deep waters. They have become a possible alternative solution for submarine infrastructure due to its thermal insulation capacity. This contribute to preventing the pipeline from clogging due to the difference in temperature between reservoir fluids and water at the bottom of the sea. The pipelines in ultra-deepwater are continually exposed to severe operating conditions, such as the effect of high levels of external pressure that can cause local deformation or even collapse of the pipe. Thus, a greater understanding of the mechanical behavior of sandwich pipes is required. This paper presents a FEM-based evaluation of friction and initial imperfection effects on sandwich pipes local buckling. The non-linear evaluation was carried out in FEM of local buckling of two sandwich pipes, with polypropylene and cement as filled annular material. The influence of initial imperfections and the degree of friction, between the annular material and the steel pipes, as well as geometric variations of the pipe were considered. The numerical simulations results indicate a capacity to withstand ultra-deep waters collapsing pressures, around 3000 m, either for polypropylene or cement filled annular material model. In addition, the results indicate that the collapse pressure is inversely proportional to the increase in annular thickness and directly proportional to the decrease in friction which have an impact and contribution on the carrying capacity of the sandwich pipe. Further research will consider a design of experiments analysis of reported effects for different diameter-to-thickness ratios.

The Evolving Role of Oil and Gas Companies in the Energy Industry

This paper provides a review of the evolving role and characteristics of the global oil and gas companies, which increasingly come in a variety of flavors. It also surveys the different types of global oil and gas companies that include national oil companies (NOCs), international oil companies (IOCs), Independents, and oilfield services companies (OFSCs). The continued rise of NOCs, accelerated by high oil prices, has seen the balance of control over most of the world’s hydrocarbon resources shift decisively in their favor. Their ability to access capital, human resources and technical services directly from oil field service companies, and to build in-house competencies, allows them to operate independently of Investor Owned Companies in most instances. The demand on NOCs continues to evolve with the global energy landscape to reflect variations in demand, discovery of new ultra-deep water oil deposits, and national and geopolitical developments. NOCs, traditionally viewed as the custodians of their country's natural resources, have generally owned and managed the complete national oil and gas supply chain from upstream to downstream activities. Having secured their home base, NOCs have emerged as joint venture partners with the IOCs and increasingly as their competitors, seeking international upstream and downstream acquisition and asset targets. The key question is whether this emerging landscape will undermine the sustainability of the IOC resource-ownership business model. Are the challenges of declining production in existing oil fields replacing oil and gas reserves in restricted access or higher cost areas, and the declining of the operating profit margins yet sufficient to reach a tipping point?

Investigation of the Effects of Flowline Sizes, Flow Rates, Insulation Material, Type and Configuration on Flow Assurance of Waxy Crude

The recovery of hydrocarbons has gone into deep and ultra-deep waters. Typically, operations from such an environment make the system susceptible to flow assurance challenges. Operations with long subsea flowlines need special attention with respect to flow assurance problems, especially with respect to wax deposition and risk of hydrate formation. As a result, during such operations, it becomes very crucial to evaluate the flowline sizes, flow rates and subsea flowline lengths to minimize flow assurance problems. For the wax deposition control, the operating temperature must be maintained above wax appearance temperature (WAT) by either insulation or electrical heating depending on the cost and energy efficiency factors. In this study, several multiphase simulations were carried out using PIPESIM software to investigate the effects of flowline sizes, flow rates, insulation material, type and configuration on flow assurance of waxy crude over 10.2 km between the wellhead and the first stage separator on the platform. Considering the implications of these factors for flow assurance. The data and results obtained from this study suggest that line size of 0.29 m, the flow rate of 3280 m 3 /d, poly-urethane foam, and pipe-in-pipe insulation type are favourable to flow assurance of waxy crude with respect to maintaining the temperature of the fluids above the wax appearance temperature of 26 o C; and also to deliver the fluids to the platform at the recommended pressure of over 11 bar. Keywords: Waxy Crude. Flow Assurance. Flow Rates. PIPESIM software, wax control. DOI: 10.7176/ISDE/11-3-02 Publication date: April 30 th 2020

Postulated failure analyses of a spread-moored semi-submersible

Semi-submersibles, best-suitable for oil and gas exploration in ultra-deep waters, possess attractive stability characteristics. While well-defined installation practices also bound them, failure of mooring lines shall pose challenges to their functional safety. Postulated failure analyses of a semi-submersible in 1500 m water depth in the Gulf of Mexico, installed with two other moorings namely: spread catenary and taut-moored, are discussed, and the fatigue damage is estimated using S–N curve approach. Results showed that while the motion responses of the semi-submersible with the proposed spread mooring are within the permissible limits, the fatigue life of the remaining mooring under the postulated failure condition is significantly decreased. Results show that the motion responses of semi-submersible with the proposed spread mooring are found to be within the permissible limits, except for a marginal increase under the mooring failure case. Tension in the remaining mooring lines is found to be dependent on the position of the failed mooring lines.

Predicting the wet collapse pressure for flexible risers with initial ovalization and gap: An analytical solution

As offshore hydrocarbon production moves towards ultra-deep water, flexible risers have to withstand the huge hydro-static pressure without collapse. They are designed with strong collapse capacities, allowing them to operate under the condition where their annuli are flooded by the seawater. However, initial imperfections can weaken the collapse capacity under such a flooded condition, triggering the so-called “wet collapse”. Two common initial imperfections, the carcass ovality and the radial gap between the carcass and pressure armor, would reduce the collapse strength of flexible risers significantly. Mostly, collapse analyses are performed through numerical simulations, which are less feasible for the design stage of flexible risers comparing with analytical models. To date, there are few analytical models available in public literature to predict the wet collapse pressure of flexible risers accounting for initial ovality and gap. To meet this demand, an analytical model is established in this paper to address these issues. This model is developed as a spring-supported arch, solving the collapse pressure with stability theories of ring and arched structures. This analytical model is verified by numerical simulations, which gives prediction results that correlate well with the numerical ones.

Salt Rock: a Strategic Geomaterial in Brazil

This paper presents a new challenge under study in Brazil: the offshore storage of natural gas and CO2 in salt (halite) caverns opened by solution mining in shallow and ultradeep water. The salt rock mechanics in Brazil started with the underground mining of sylvinite (NaCl.KCL) overlying tachyhydrite (CaCl2.MgCl2.12H2O) and research initiated in the 1970s (Costa 1984), to enable the mining of this ore. Applying a numerical simulation of drilling and excavation, the exploration and operation of mines were possible for more than 35 years. The same technology has also been used in the stability analysis of several salt caverns opened by solution mining of halite (NaCl). With the discovery of the giant pre-salt reservoirs in Brazil, underlying about 2000 m of stratified salt rocks, with the presence of tachyhydrite, all the knowledge acquired in the conventional and solution mining designs was ready to be used. More than 200 pre-salt wells have been designed and drilled successfully using the same methodology and computer codes. These approaches are proposed here as a solution to the presented challenge.

Synthesis of new CO2 hydrate inhibitors

Gas hydrate is a crystalline compound made of water and mainly of gases methane and carbon dioxide under specific conditions of pressure and temperature. Increasing worldwide petroleum exploitation in deep waters, where these conditions are encountered, favours the precipitation of gas hydrate in seafloor pipelines, resulting in partial or total obstruction of petroleum flow. Brazil's largest petroleum reserves of the pre-salt interval, for example, are located in ultra-deep waters (>1500 m) and may have a gas composition of up to 80% of CO2. Huge investments are necessary to inhibit the formation of gas hydrate and to assure petroleum flow in pipelines. Here we present the results of the synthesis of new organic compounds obtained from L-Threonine, which show a high potential to be used as CO2 hydrate inhibitors. This characteristic is related to the increase carbon chain in each molecule (higher hydrophobicity) leading to a reduction on CO2 solubility in water. In addition to that, our study also shows the occurrence of the “salting out effect” and reduced water activity coefficient.

New risk control mechanism for innovative deepwater artificial seabed system through online risk monitoring system

The current offshore field development concepts (dry tree or subsea tree) have limitations for petroleum production in ultra-deep water (more than 1500 m), where the challenges are characterized by the depth of water, remoteness and harsh environmental conditions. A new alternative offshore field development solution, termed as Deepwater Artificial Seabed (DAS) system, is proposed. The new DAS system offers improved technical and commercial performance, higher levels of safety, reduced interface complexity and improved development flexibility for field development in deep and ultra-deep water. Central to the evaluation and application of the new DAS system is the inherent risk relative to the acceptance level. Hence, barriers in the new DAS system are established and maintained to prevent, control or mitigate undesired events or accidents. This paper investigates a new risk control mechanism for the innovative DAS system in accordance with the online risk monitoring and decision support principle. Firstly, main characteristics and design principle of the DAS system are presented. On this basis, the main hazards for the DAS system are identified, which includes well incident/ loss of well control, mooring system failure, ballast system failure, leak from riser, flexible jumper and subsea production facilities, and damage to riser, flexible jumper and subsea production facilities. The risk level of the identified hazards related to offshore petroleum systems already in use is analyzed and presented by the results from the risk assessment for the Norwegian Continental Shelf (NCS) in the period of 2008–2017. It has been demonstrated that the risk associated with the key sub-systems including the ballast system, mooring system, well system and external impact protection system is at a level that calls for further risk reduction. This is followed by the barrier management principles as well as a discussion of existing and potential barriers in the DAS system. Improved barrier functions in the key sub-systems are analyzed systematically and proposals for alternative barrier functions are suggested based on the online risk modeling and decision support principle. Further, a case study in regard to the DAS mooring system failure event is conducted to demonstrate how the new risk control mechanism works. The proposed new risk control mechanism could improve the safety of the DAS system and convince the offshore petroleum industry for application significantly.

A study on the simulation-based installation shape design method of steel lazy wave riser (SLWR) in ultra deepwater depth

Steel Lazy Wave Riser (SLWR), which is a kind of ultra deepwater riser system, is a slender structure with length of over 2,000m. The shape design of the SLWR is very important for operational stability of the SLWR, because the SLWR has strong structural characteristics and are affected by various ocean environmental loads. In this research, the simulation-based design process is studied to find the optimal shape of SLWR at the installation. First, available parameters and responses are derived and the dynamic characteristics of them were analyzed to select the effective parameters on the responses using multibody dynamic simulation. Second, the simulation-based design framework for shape design of the SLWR was developed using opensource-based PIDO(Process Integration and Design Optimization) software, and developed dynamic simulation model. Finally, the shape design of the SLWR at the installation was performed using the developed design framework.

Efficient acoustic-elastic FD coupling method for anisotropic media

Pre-salt discoveries are among the most important in the world over the last decade and ultra-deep water offshore exploration targets became common in oil industry. In these cases, the water layer typically compounds 30–40% of the whole geophysical region of interest. The most successful numerical schemes to model seismic waves in these regions are based on ordinary staggered-grid schemes (OSG). Nevertheless, these formulations have the drawback of requiring higher memory storage, since they need to save both velocity and stress components. Recently, we presented equivalent staggered-grid schemes (ESG) that allow memory storage reduction and/or higher computational efficiency depending on the specific case. Specially, the acoustic ESG has lower memory requirement and is the most efficient one. In order to improve the efficiency and reduce memory storage requirement in offshore regions, the present paper develops an explicit direct acoustic-elastic coupling to solve anisotropic wave equations. A domain decomposition is used, where the geophysical medium is divided in two different subdomains, one acoustic, related to water layer, and the other elastic, related to rock layers, considered as vertical-transverse isotropic (VTI) media. The best computational efficiency is achieved by choosing a flat-horizontal interface to couple the two subdomains. The former subdomain is modeled using the acoustic ESG and the second subdomain is modeled using the OSG for VTI media. Both schemes have the same stability properties and the resulting coupling algorithm has the same stability and accuracy as the original OSG applied to the whole model. The proposed method applies to 3D case up to orthorhombic case. To validate the method, it was applied to the Hess VTI model with water layer extended to compound 35% of the model. The reduction observed was near to 25% in memory and in CPU time and grows with percentage of water in the model.

Rheology of THF hydrate slurries at high pressure

One of the main issues in the area of drilling and production in deep and ultra-deep water in the oil industry is the formation of natural gas hydrates. Hydrates are crystalline structures resembling ice, which are usually formed in conditions of high pressure and low temperature. Once these structures are formed, they can grow and agglomerate, forming plugs that can eventually completely or partially block the production lines, causing huge financial losses. To predict flow behavior of these fluids inside the production lines, it is necessary to understand their mechanical behavior. This work analyzes the rheological behavior of hydrates slurries formed by a mixture of water and Tetrahydrofuran (THF) under high pressure and low temperature conditions, close to the ones found in deep water oil exploration. The THF hydrates form similar structures as the hydrates originally formed in the water-in-oil emulsions in the presence of natural gas, at extreme conditions of high pressure and low temperature. The experiments revealed some important issues that need to be taken into account in the rheological measurements. The results obtained show that the hydrate slurry viscosity increases with pressure. Oscillatory tests showed that elasticity and yield stress also increase with pressure.

Phase Equilibria Data and Thermodynamic Analysis for Liquid–Hydrate–Vapor (LHV) with High Ethanol Concentrations

Significant portions of the oil reserves in Brazil are located in deep or ultradeep waters. Oil production from these reservoirs implies a constant awareness of gas hydrate formation. The petroleum...

Parametric studies on the impact response of offshore triceratops in ultra-deep waters

This paper addresses the parametric studies on the impact response of offshore triceratops subjected to low-velocity impact. Triceratops is the object of the present impact study which is one of the new generation offshore complaint platforms with three buoyant legs connected to deck by ball joints. The innovative geometric form and compliant characteristics distinguish triceratops from conventional offshore platforms. The buoyant legs in triceratops are usually designed as orthogonally stiffened cylindrical shell structures. Numerical studies are carried out using Ansys Explicit analysis solver to predict the impact response and local damage of buoyant leg of triceratops. From the impact force time history obtained through explicit analysis, the hydrodynamic time response analysis is carried out in Ansys Aqwa to predict the response of deck and buoyant legs. Parametric studies are mainly focussed on the effect on the location of the indenter, size of the indenter, type of indenter, number of stiffeners and strain-rate definition. Force displacement curves are reported along with detailed numerical observations.

An experimental study on doubly salt effect for methane hydrate inhibition

An experimental study on the effect of ionic liquids that are used for gas hydrate inhibition purposes in deep and ultra-deep water natural gas pipelines in which either regular water or seawater is present. Due to their physicochemical properties, 1-ethyl-3-methylimidazolium methylsulphonate and 1-ethyl-3-methylimidazolium dicynamide were selected as hydrate inhibitors in this work. Experimental gas hydrate equilibrium curves are obtained for thermodynamic and kinetic inhibition performances for ionic liquids, which are interacting with both regular and salty water in studied case studies. Moreover, obtained experimental results are compared with current standard chemical agents that are used for the same intended inhibition purpose. On the other hand, the performance of low dosage synergent materials on both thermodynamic and kinetic inhibition were studied in details and compared with previous studies. The characteristics of the studied inhibition processes were analysed in terms of the type of ionic liquid, synergent material and type of water.

Caracterização de Eletrofácies em Coquinas Lacustres e Depósitos Híbridos de Fase Rifte: Pré-Sal, Cretáceo inferior, Bacia de Campos, Brasil

This study presents electrofacies models for two wells with cores and sidewall cores of Coqueiros Formation, lower Cretaceous of Campos Basin. The WELL-1 is located in deep water of the south of the basin and is composed by bioclastic carbonate, siliciclastic and hybrid rocks. The electrofacies modelling distinguished four electrofacies, which are correlated to the lithofacies coquina, hybrid rock, siliciclastic mudstone, and sandstone. The WELL-2 is situated in ultra-deep water of the north of the basin and is essentially constituted of bioclastic carbonates. The electrofacies modelling for this well differentiated four electrofacies, which are correlated to the lithofacies mudstone, coquina with carbonate mud, coquina with moderate to high degree of shell fragmentation and/or oriented shells, and poorly sorted massive coquina with variable degree of shell fragmentation. This study showed that it is possible to distinguish, with high level of accuracy, bioclastic carbonate rocks from siliciclastic and hybrid rocks based on the well logs. The electrofacies analysis distinguished particle-supported carbonate rocks from mud-supported ones. It was also possible to separate bioclastic carbonate rock with different taphonomic criteria, such as organization and degree of shell fragmentation. The electrofacies model showed to be a useful tool to interpret geological intervals in wells without rock samples. Nevertheless, it will never represent all the numerous depositional facies, and thus it can not completely replace the rock sampling in detailed sedimentological and reservoir studies.

Technical and Non-technical Challenges of Development of Offshore Petroleum Reservoirs: Characterization and Production

Offshore oil and gas reservoirs comprise a significant portion of the world’s reserve base, and their development is expected to help close a potential gap in the supply of hydrocarbons in the near future. Continuous advances in technology have helped the oil and gas industry to extend the exploration and production activities to deep and ultra-deep waters in harsher environments. Field development in the offshore environment is associated with numerous significant challenges in different phases including exploration, reservoir description and characterization, development planning, drilling, production, improved oil recovery (IOR) and enhanced oil recovery (EOR), transportation, and decommissioning. These challenges are further complicated by economic restrictions, especially in periods when low or unstable oil prices weaken the incentives of investments due to the high risks and uncertainties involved. Environmental concerns including the adverse effects of seismic surveys, drilling activities, discharge of waste material and produced water, and accidental spills and blowouts add another level of complexity to the design and implementation of offshore projects. Safe, reliable, and efficient development of offshore hydrocarbon reservoirs can be achieved through the proper identification of the challenges and use of modern technologies and innovative methods. This work is an effort to provide a comprehensive review of the history, global distribution, production share, classification, characteristics, and characterization methods of offshore reservoirs, and some of the main aspects and challenges of the experimental and modeling works as well as IOR/EOR planning and implementations from the reservoir engineering and production standpoint. These challenges are categorized based on their area of impact, i.e., characterization and recovery (production) phases. Furthermore, economic and environmental challenges are reviewed. After the recent downturn that caused a decline in offshore investments, current investment trends and the forecasts show that the offshore industry is booming again with more focus on cost saving and operational efficiency. The key technologies that can expedite the growth of the offshore petroleum industry have also been discussed.

Lacustrine coquinas and hybrid deposits from rift phase: Pre-Salt, lower Cretaceous, Campos Basin, Brazil

This study presents a facies characterization, facies succession and conceptual depositional model of the Coqueiros Formation, Lower Cretaceous of Campos Basin, based on core analyses of two wells. WELL-1 is a shallow water drilling located at south of Campos Basin within the Badejo structural high, and WELL-2 is an ultra deep water drilling located at north, over the “External High”. Ten carbonate facies, three siliciclastic facies, two magnesium clay mineral rich facies and two hybrid facies were identified. The carbonate facies were defined as rudstone, grainstone, packstone and mud supported carbonate rock, composed of bivalves, ostracods, and rare gastropods. Bivalve shells, mostly disarticulated with distinct degrees of fragmentation, characterized the main components of the ten carbonate facies. The siliciclastic facies are sandstones and mudstones, which occur locally. The magnesium clay rich facies is composed by stevensitic claystone and arenites. The mixture of bioclasts, siliciclastic grains, stevensite ooids and peloids constitute hybrid facies. The depositional processes involved waves and storm currents, as well as storm refluxes and tectonically-driven gravitational deposits, which mixed particles from different basinal sites producing the hybrid facies. The conceptual depositional model for each geological setting were elaborated based on facies stacking pattern analysis. A hybrid ramp in rift setting, studied in WELL-1, is characterized by carbonate, argillaceous, siliciclastic and hybrid successions, suggesting a strong terrigenous influence and variation of the lake water chemistry. An isolated bioclastic high in a rift setting, studied in WELL-2, is basically constructed by bioclastic sequences with local occurrence of siliciclastic mudstones deposited from hypopycnal plumes in relatively deep water. The extraordinary dominance of bivalve mollusks occurred during the lower Aptian stage in Campos Basin, in an active rift basin, with robust bioclastic productivity within protected basement highs. In structures near to the lake border, predominated siliciclastic and hybrid rock sequences as a result of high structural gradients and terrigenous input. Isolated highs from lakeshores were protected from external terrigenous influence. In lacustrine deep water bioclastic and hybrid arenites were deposited as fans generated by gravitational flows triggered by destabilization of shallower water deposits during episodic storms and tectonic activities. This study of the coquina deposits constructional model within a nearshore and also in a offshore lacustrine system is a useful knowledge for the understanding of coquina reservoir distribution and is applicable in the exploratory investigation of new areas with correlate lacustrine systems.