Novo método para estimativa do gradiente de fratura para poços de petróleo

The development of oil wells drilling requires additional cares mainly if the drilling is in offshore ultra deep water with low overburden pressure gradients which cause low fracture gradients and, consequently, difficult the well drilling by the reduction of the operational window. To minimize, in the well planning phases, the difficulties faced by the drilling in those sceneries, indirect models are used to estimate fracture gradient that foresees approximate values for leakoff tests. These models generate curves of geopressures that allow detailed analysis of the pressure behavior for the whole well. Most of these models are based on the Terzaghi equation, just differentiating in the determination of the values of rock tension coefficient. This work proposes an alternative method for prediction of fracture pressure gradient based on a geometric correlation that relates the pressure gradients proportionally for a given depth and extrapolates it for the whole well depth, meaning that theses parameters vary in a fixed proportion. The model is based on the application of analytical proportion segments corresponding to the differential pressure related to the rock tension. The study shows that the proposed analytical proportion segments reaches values of fracture gradient with good agreement with those available for leakoff tests in the field area. The obtained results were compared with twelve different indirect models for fracture pressure gradient prediction based on the compacting effect. For this, a software was developed using Matlab language. The comparison was also made varying the water depth from zero (onshore wellbores) to 1500 meters. The leakoff tests are also used to compare the different methods including the one proposed in this work. The presented work gives good results for error analysis compared to other methods and, due to its simplicity, justify its possible application

Caracterização tectono-estratigráfica da sequência transicional na sub-bacia de Sergipe

This thesis deals with the tectonic-stratigraphic evolution of the Transitional Sequence in the Sergipe Sub-basin (the southern segment of the Sergipe-Alagoas Basin, Northeast Brazil), deposited in the time interval of the upper Alagoas/Aptian stage. Sequence boundaries and higher order internal sequences were identified, as well as the structures that affect or control its deposition. This integrated approach aimed to characterize the geodynamic setting and processes active during deposition of the Transitional Sequence, and its relations with the evolutionary tectonic stages recognized in the East Brazilian Margin basins. This subject addresses more general questions discussed in the literature, regarding the evolution from the Rift to the Drift stages, the expression and significance of the breakup unconformity, the relationships between sedimentation and tectonics at extensional settings, as well as the control on subsidence processes during this time interval. The tectonic-stratigraphic analysis of the Transitional Sequence was based on seismic sections and well logs, distributed along the Sergipe Sub-basin (SBSE). Geoseismic sections and seismic facies analysis, stratigraphic profiles and sections, were compiled through the main structural blocks of this sub-basin. These products support the depositional and tectonic-stratigraphic evolutionary models built for this sequence. The structural analysis highlighted similarities in deformation styles and kinematics during deposition of the Rift and Transitional sequences, pointing to continuing lithospheric extensional processes along a NW trend (X strain axis) until the end of deposition of the latter sequence was finished by the end of late Aptian. The late stage of extension/rifting was marked by (i) continuous (or as pulses) fault activity along the basin, controling subsidence and creation of depositional space, thereby characterizing upper crustal thinning and (ii) sagstyle deposition of the Transitional Sequence at a larger scale, reflecting the ductile stretching and thinnning of lower and sub crustal layers combined with an increasing importance of the thermal subsidence regime. Besides the late increments of rift tectonics, the Transitional Sequence is also affected by reactivation of the border faults of SBSE, during and after deposition of the Riachuelo Formation (lower section of the Transgressive Marine Sequence, of Albian age). It is possible that this reactivation reflects (through stress propagation along the newlycreated continental margin) the rifting processes still active further north, between the Alagoas Sub-basin and the Pernambuco-Paraíba Basin. The evaporitic beds of the Transitional Sequence contributed to the development of post-rift structures related to halokinesis and the continental margin collapse, affecting strata of the overlying marine sequences during the Middle Albian to the Maastrichtian, or even the Paleogene time interval. The stratigraphic analysis evidenced 5 depositional sequences of higher order, whose vertical succession indicates an upward increase of the base level, marked by deposition of continental siliciclastic systems overlain by lagunar-evaporitic and restricted marine systems, indicating that the Transitional Sequence was deposited during relative increase of the eustatic sea level. At a 2nd order cycle, the Transitional Sequence may represent the initial deposition of a Transgressive Systems Tract, whose passage to a Marine Transgressive Sequence would also be marked by the drowning of the depositional systems. At a 3rd order cycle, the sequence boundary corresponds to a local unconformity that laterally grades to a widespread correlative conformity. This boundary surface corresponds to a breakup unconformity , being equivalent to the Pre-Albian Unconformity at the SBSE and contrasting with the outstanding Pre-upper Alagoas Unconformity at the base of the Transitional Sequence; the latter is alternatively referred, in the literature, as the breakup unconformity. This Thesis supports the Pre-Albian Unconformity as marker of a major change in the (Rift-Drift) depositional and tectonic setting at SBSE, with equivalent but also diachronous boundary surfaces in other basins of the Atlantic margin. The Pre-upper Alagoas Unconformity developed due to astenosphere uplift (heating under high lithospheric extension rates) and post-dates the last major fault pulse and subsequent extensive block erosion. Later on, the number and net slip of active faults significantly decrease. At deep to ultra deep water basin segments, seaward-dipping reflectors (SDRs) are unconformably overlain by the seismic horizons correlated to the Transitional Sequence. The SDRs volcanic rocks overly (at least in part) continental crust and are tentatively ascribed to melting by adiabatic decompression of the rising astenospheric mantle. Even though being a major feature of SBSE (and possibly of other basins), the Pre-upper Alagoas Unconformity do not correspond to the end of lithospheric extension processes and beginning of seafloor spreading, as shown by the crustal-scale extensional structures that post-date the Transitional Sequence. Based on this whole context, deposition of the Transitional Sequence is better placed at a late interval of the Rift Stage, with the advance of an epicontinental sea over a crustal segment still undergoing extension. Along this segment, sedimentation was controled by a combination of thermal and mechanical subsidence. In continuation, the creation of oceanic lithosphere led to a decline in the mechanical subsidence component, extension was transferred to the mesoceanic ridge and the newly-formed continental margin (and the corresponding Marine Sequence) began to be controlled exclusively by the thermal subsidence component. Classical concepts, multidisciplinary data and new architectural and evolutionary crustal models can be reconciled and better understood under these lines

Novo método para estimativa do gradiente de fratura para poços de petróleo

The development of oil wells drilling requires additional cares mainly if the drilling is in offshore ultra deep water with low overburden pressure gradients which cause low fracture gradients and, consequently, difficult the well drilling by the reduction of the operational window. To minimize, in the well planning phases, the difficulties faced by the drilling in those sceneries, indirect models are used to estimate fracture gradient that foresees approximate values for leakoff tests. These models generate curves of geopressures that allow detailed analysis of the pressure behavior for the whole well. Most of these models are based on the Terzaghi equation, just differentiating in the determination of the values of rock tension coefficient. This work proposes an alternative method for prediction of fracture pressure gradient based on a geometric correlation that relates the pressure gradients proportionally for a given depth and extrapolates it for the whole well depth, meaning that theses parameters vary in a fixed proportion. The model is based on the application of analytical proportion segments corresponding to the differential pressure related to the rock tension. The study shows that the proposed analytical proportion segments reaches values of fracture gradient with good agreement with those available for leakoff tests in the field area. The obtained results were compared with twelve different indirect models for fracture pressure gradient prediction based on the compacting effect. For this, a software was developed using Matlab language. The comparison was also made varying the water depth from zero (onshore wellbores) to 1500 meters. The leakoff tests are also used to compare the different methods including the one proposed in this work. The presented work gives good results for error analysis compared to other methods and, due to its simplicity, justify its possible application

Estudo da viabilidade econômica em campos maduros

When it comes to oil and gas in Brazil is almost certain that we are referring to activities in deep waters off the coast of Campos, Rio de Janeiro, the main field of action of PETROBRAS and a small number of multinational oil companies . Since the Law 9.478/97 allows, by means of concessions, that other companies other than Petrobras, to explore and produce oil and gas domestically. Soon it moved, then the private companies that want small and medium-sized businesses to invest in such activities, forming a segment of independent producers, as occurs in other countries. In this context, this work aims at making an economic feasibility study, is currently analyzing how this thread and focus on the factors that contribute to its development as well as those that constitute barriers. To this end, we conducted a survey examining some mature fields that are in production in order to capture cost information in the phases of project, operation and abandonment. The work also presents an analysis of the results obtained in the survey, identifying the costs higher. With the results obtained through the study used economic engineering tools such as NPV and IRR, using a variety of design scenarios, to study the economic viability of these fields. In scenario 4 was set a production of 4.0 m³ / d of oil, which is an expected average production for several of these fields, whose minimum value of a barrel of oil, to enable this field, was $ 55.00, this value well below what was being practiced in the market today.

Classificação de imagens de ambientes coralinos: uma abordagem empregando uma combinação de classificadores e máquina de vetor de suporte

The use of the maps obtained from remote sensing orbital images submitted to digital processing became fundamental to optimize conservation and monitoring actions of the coral reefs. However, the accuracy reached in the mapping of submerged areas is limited by variation of the water column that degrades the signal received by the orbital sensor and introduces errors in the final result of the classification. The limited capacity of the traditional methods based on conventional statistical techniques to solve the problems related to the inter-classes took the search of alternative strategies in the area of the Computational Intelligence. In this work an ensemble classifiers was built based on the combination of Support Vector Machines and Minimum Distance Classifier with the objective of classifying remotely sensed images of coral reefs ecosystem. The system is composed by three stages, through which the progressive refinement of the classification process happens. The patterns that received an ambiguous classification in a certain stage of the process were revalued in the subsequent stage. The prediction non ambiguous for all the data happened through the reduction or elimination of the false positive. The images were classified into five bottom-types: deep water; under-water corals; inter-tidal corals; algal and sandy bottom. The highest overall accuracy (89%) was obtained from SVM with polynomial kernel. The accuracy of the classified image was compared through the use of error matrix to the results obtained by the application of other classification methods based on a single classifier (neural network and the k-means algorithm). In the final, the comparison of results achieved demonstrated the potential of the ensemble classifiers as a tool of classification of images from submerged areas subject to the noise caused by atmospheric effects and the water column

Desenvolvimento de uma ferramenta computacional para aplicação em métodos de elevação por bombeio centrífugo submerso

The Electrical Submersible Pump (ESP) has been one of the most appropriate solutions for lifting method in onshore and offshore applications. The typical features for this application are adverse temperature, viscosity fluids and gas environments. The difficulties in equipments maintenance and setup contributing to increasing costs of oil production in deep water, therefore, the optimization through automation can be a excellent approach for decrease costs and failures in subsurface equipment. This work describe a computer simulation related with the artificial lifting method ESP. This tool support the dynamic behavior of ESP approach, considering the source and electric energy transmission model for the motor, the electric motor model (including the thermal calculation), flow tubbing simulation, centrifugal pump behavior simulation with liquid nature effects and reservoir requirements. In addition, there are tri-dimensional animation for each ESP subsytem (transformer, motor, pump, seal, gas separator, command unit). This computer simulation propose a improvement for monitoring oil wells for maximization of well production. Currenty, the proprietaries simulators are based on specific equipments manufactures. Therefore, it is not possible simulation equipments of another manufactures. In the propose approach there are support for diverse kinds of manufactures equipments

Estudo da viabilidade econômica em campos maduros

When it comes to oil and gas in Brazil is almost certain that we are referring to activities in deep waters off the coast of Campos, Rio de Janeiro, the main field of action of PETROBRAS and a small number of multinational oil companies . Since the Law 9.478/97 allows, by means of concessions, that other companies other than Petrobras, to explore and produce oil and gas domestically. Soon it moved, then the private companies that want small and medium-sized businesses to invest in such activities, forming a segment of independent producers, as occurs in other countries. In this context, this work aims at making an economic feasibility study, is currently analyzing how this thread and focus on the factors that contribute to its development as well as those that constitute barriers. To this end, we conducted a survey examining some mature fields that are in production in order to capture cost information in the phases of project, operation and abandonment. The work also presents an analysis of the results obtained in the survey, identifying the costs higher. With the results obtained through the study used economic engineering tools such as NPV and IRR, using a variety of design scenarios, to study the economic viability of these fields. In scenario 4 was set a production of 4.0 m³ / d of oil, which is an expected average production for several of these fields, whose minimum value of a barrel of oil, to enable this field, was $ 55.00, this value well below what was being practiced in the market today.

A tutela constitucional da exploração de petróleo em águas internacionais em face do princípio do desenvolvimento sustentável: a possibilidade de responsabilização civil do dano futuro

The demands brought by a society doomed to the constant production of global risks, which whose effects are not immediately noticed effects are not perceived immediately, claim from the Law a new Theory about the Risk, that would offer a broad environmental protection, at the same time it would still be compatible with the idea of economic efficiency, required by the Modern Industry. The expansion of the methods and technologies regarding the exploitation and production of oil causes the constant expansion of the exploitable boundaries, especially in ultra-deep waters with the Pre-salt layer, in Brazil, or the still incipient research about the polymetallic nodules and other mineral sources in international waters, like the Atlântico Sudoeste, by the Programme on Ocean Science in Relation do Non Living Resources (OSNLR), a global study performed in partnership with the Intergovernmental Oceanographic Commission, from UNESCO (IOC UNESCO) and also with the Division of Ocean Affairs and Law of the Sea (UNDOALOS). Thus, we aim to analyze the correlation, and possible collisions between the right to a balanced environment and the free exercise of economic activity and the occurrence of environmental damages from the perspective of the exploitation activities of oil and other natural resources in international waters, specifically in the Area, from the constitutional principle of sustainable development and its legitimacy by the environmental international protection. Therefore, this study also aims to evaluate the legal framework for exploration and production of oil in international waters, particularly in the Area, and appraise how the constitutional instruments and mechanisms for environmental protection can impact on the international environmental protection system in order to ensure the present and future generations an ecologically balanced environment, laid down in Article 225 of the Brazilian Constitution, even with so many risks posed by the activities of exploitation and production of oil in international waters. In the meantime, we intend to also intend to investigate the possibility of future liability for environmental damage in order to ensure that constitutional principle and, consequently, and try to define the concept of environmental damage and its implications on the constitutional principle of environmental protection. Given all that was in summary, this work aims to contribute to the evolution of the new Theory of Environmental Risk, turning the law into something more than a punitive or corrective element in this society, but into a legal risk management, that may be triggered even before the consolidation of the damage

Habitabilidade na cidade sobre as águas: desafios da implantação de infra-estrutura de saneamento nas palafitas do Igarapé do Quarenta bairro Japiim Manaus/AM

The present research if inserts in the subject of the habitation of social interest and its relation with the sanitation infra-structure questions (sewer, water, draining and garbage). Having as study universe the narrow river of the Forty , situated one in the city of Manaus, capital of Amazon, approaches questions that if present between the necessities of housing and the especificidades of the natural environment, whose characteristics evidence limits for the implantation of adequate habitations. The objective is to analyze the possibilities and the limits of the urbanística regularization in the palafitas of the narrow rivers of Manaus, in view of the factors of habitability and ambient protection, expresses for the sanitation system - sanitary exhaustion, water supply, urban draining and garbage collection. The work approaches initially relative the conceptual aspects to the subject of social habitation in the country and its relation with the habitability factors, also focusing the question of the housing and the processes of urban informality in the city of Manaus. It deals with the process of constitution of the palafitas in the space of the city and its relation with the habitacionais politics, presenting the analysis of the implantation of the palafitas in relation to the sanitation infra-structure conditions (sewer, water, draining and garbage). As conclusion, it identifies to the possibilities and limits of urbanística regularization of the palafitas implanted to the long one of the narrow river of the Forty , taking in consideration the systems of the sanitation infrastructure

Uso de argilominerais e diatomita como adsorvente de fenóis em águas produzidas na indústria de petróleo

The oil production in Brazil has been increasing each year. Consequently, increasing volumes of water produced are generated with large quantities of contaminants, which brings many problems in disposing of these waters. The concern that the concentrations of contaminants in water produced meet existing laws for disposal of effluents, has been extremely important for the development of different techniques for treatment of water produced. The study of clay minerals as adsorbents of organic contaminants has grown considerably so in order to combine the low cost with the efficiency of environmental preservation and health issues. Thus, this study aims to understand the characteristics of vermiculite clay, sodium bentonite, calcium bentonite and diatomite and evaluate their performance as adsorbents for phenol in the water produced. Through adsorption isotherms it was possible to observe the behavior of these adsorptive clay and diatomite for adsorption of phenol, the main phenolic compound found in water produced. Different concentrations of synthetic solutions of phenol were put in touch with these adsorbents under same conditions of agitation and temperature. The adsorbents were composted adsorptive favorable, but the vermiculite and diatomite showed little capacity for absorption, being suggested for absorbs small concentrations of phenol in the balance isothermal

Cinemática de partículas em fluidos de viscosidade variável com o tempo e sua aplicação na construção de poços de petróleo: avaliação durante paradas operacionais

The new oil reservoirs discoveries in onshore and ultra deep water offshore fields and complex trajectories require the optimization of procedures to reduce the stops operation during the well drilling, especially because the platforms and equipment high cost, and risks which are inherent to the operation. Among the most important aspects stands out the drilling fluids project and their behavior against different situations that may occur during the process. By means of sedimentation experiments, a correlation has been validated to determe the sedimentation particles velocity in variable viscosity fluids over time, applying the correction due to effective viscosity that is a shear rate and time function. The viscosity evolution over time was obtained by carrying out rheologic tests using a fixed shear rate, small enough to not interfere in the fluid gelling process. With the sedimentation particles velocity and the fluid viscosity over time equations an iterative procedure was proposed to determine the particles displacement over time. These equations were implemented in a case study to simulate the cuttings sedimentation generated in the oil well drilling during stops operation, especially in the connections and tripping, allowing the drilling fluid project in order to maintain the cuttings in suspension, avoiding risks, such as stuck pipe and in more drastic conditions, the loss of the well

Rejeito de xisto como adsorvente para remoção de fenol em águas produzidas na indústria de petróleo

Produced water is the main effluent linked to the activity of extraction of oil and their caring management is necessary due to the large volume involved, to ensure to minimize the negative impacts of discharges of these waters in the environment. This study aimed to analyze the use of retorted shale, which is a reject from the pyrolysis of pirobituminous shale, as adsorbent for the removal of phenols in produced water. The material was characterized by different techniques (grain sized analysis, thermal analysis, BET, FRX, FT-IR, XRD and SEM), showing the heterogeneity in their composition, showing its potential for the removal of varied compounds, as well as the phenols and their derivatives. For the analysis of the efficiency of the oil shale for the adsorption process, assays of adsorption balance were carried through, and also kinetic studies and dynamics adsorption, in the ETE of the UTPF of Petrobras, in Guamaré-RN. The balance assays shown a bigger conformity with the model of Langmuir and the kinetic model more adjusted to describe the adsorption of phenols in retorted shale was of pseudo-second order. The retorted shale presented a low capacity of adsorption of phenols (1,3mg/g), when related to others conventional adsorbents, however it is enough to the removal of these composites in concentrations presented in the produced water of the UTPF of Guamaré. The assays of dynamics adsorption in field had shown that the concentration of phenol in the effluent was null until reaching its rupture (58 hours). The results showed the possibility of use of the reject for removal of phenols in the final operations of the treatment process, removing as well, satisfactorily, the color and turbidity of the produced water, with more than 90% of removal

Estudo de adsorvente obtido de terras diatomáceas para remoção de metais pesados em águas produzidas: processamento, caracterização e dinâmica em leito fixo

The acceleration of industrial growth in recent decades on all continents aroused the interest of the companies to counter the impacts produced on the environment, spurred primarily by major disasters in the petroleum industry. In this context, the water produced is responsible for the largest volume of effluent from the production and extraction of oil and natural gas. This effluent has in its composition some critical components such as inorganic salts, heavy metals (Fe, Cu, Zn, Pb, Cd, ), presence of oil and chemicals added in the various production processes. In response to impact, have been triggered by research alternative adsorbent materials for water treatment and water produced, in order to removing oils and acids and heavy metals. Many surveys of diatomaceous earth (diatomite) in Brazil involve studies on the physico-chemical, mineral deposits, extraction, processing and applications. The official estimated Jazi are around 2.5 million tonnes, the main located in the states of Bahia (44%) and Rio Grande do Norte (37,4%). Moreover, these two states appear as large offshore producers, earning a prominent role in research of adsorbents such as diatomite for treatment of water produced. Its main applications are as an agent of filtration, adsorption of oils and greases, industrial load and thermal insulator. The objective of this work was the processing and characterization of diatomite diatomaceous earth obtained from the municipality of Macaíba-RN (known locally as tabatinga) as a low cost regenerative adsorbent for removal of heavy metals in the application of water produced treatment. In this work we adopted a methodology for batch processing, practiced by small businesses located in producing regions of Brazil. The characterization was made by X-ray diffraction (XRD), scanning electron microscopy (SEM) and specific surface area (BET). Research conducted showed that the improvement process used was effective for small volume production of diatomite concentrated. The diatomite obtained was treated by calcination at temperature of 900 oC for 2 hours, with and without fluxing Na2CO3 (4%), according to optimal results in the literature. Column adsorption experiments were conducted to percolation of the in nature, calcined and calcined fluxing diatomites. Effluent was used as a saline solution containing ions of Cu, Zn, Na, Ca and Mg simulating the composition of produced waters in the state of Rio Grande do Norte, Brazil. The breakthrough curves for simultaneous removal of copper ions and zinc as a result, 84.3% for calcined diatomite and diatomite with 97.3 % for fluxing. The calcined fluxing diatomite was more efficient permeability through the bed and removal of copper and zinc ions. The fresh diatomite had trouble with the permeability through the bed under the conditions tested, compared with the other obtained diatomite. The results are presented as promising for application in the petroleum industry

Ecologia parasitária de isópodos e biologia reprodutiva em tibiro, Oligoplites spp (OSTEICHTHYES: CARANGIDAE) das águas costeiras de Natal, Rio Grande do norte

Oligoplites palometa (Cuvier) and Oligoplites saurus (Bloch & Schneider) (Osteichthyes: Carangidae) are coastal pelagic fish species. The objective of this study was to investigate the effect of parasitism by isopods and the reproductive biology of the leather jack, Oligoplites spp. A total of 113 individuals of Oligoplites spp (35 of O. saurus and 78 of O. palometa) were captured during the period between January, 2005 and July, 2007 from the coastal waters of Natal, RN. The morphometric and meristic characters were registered; macroscopic analyses were done to collect the isopod parasites and the gonads were observed to verify the reproductive aspects. The crustacean isopod parasite, Cymothoa spinipalpa (Isopoda: Cymothidae) was encountered on the tongue in the oral cavity in both fish hosts. The parasitic indices of C. spinipalpa showed high values of prevalance of 51,4% for O. saurus and 64,1% for O. palometa. The host presented significant correlations between body mass and body length of O. palometa and the number of parasites. Body lengths of female C. spinipalpa were small due to the limited space available in the oral cavity of the host. There was a significant difference in the sex ratio of O. palometa, males outnumbered the females. The isopod parasites showed specificity to the oral cavity of hosts. Macroscopic analyses of gonads showed four stages of gonadal development for both sex of O. palometa: immature, maturing, mature and spent

Biologia reprodutiva da |Tainha, Mugil curema valencientes, 1836 (osteichthyes: mugilidade) nas águas costeiras do Rio Grande do Norte

The marine fish white mullet, Mugil curema Valenciennes, 1836 (Osteichthyes: Mugilidae) exhibits a wide geographical distribution, being common in the Brazilian coast and is an important component of the artisanal fisheries. The objective of this study was to investigate the reproductive biology of M. curema in the coastal waters of Rio Grande do Norte. Fish samples were captured on a monthly basis during August, 2008 to July, 2009. The fish specimens were numbered, weighed, measured, dissected and their gonads were removed, weighed, their sex and gonadal development were identified. The length-weight relationship was determined for males and females. The sex ratio, the size at first gonadal maturation and gonadosomatic index (GSI) were calculated and ovarian development was investigated using macroscopic and histological techniques. The fecundity, spawning type and the reproductive period of the species were determined. A total of 366 specimens (186 males and 180 females) were captured. The sex ratio was 1:1 and the females were heavier than males. The estimated values of the angular coefficient for both sexes suggest that the species has isometric growth. The size at which 50% of the population began the process of maturation was 25.9 cm of total length for grouped sex. The macroscopic characteristics of the ovaries showed four stages of development: immature, maturing, mature and spent. However, the microscopic characteristics of the ovaries showed five stages of development: immature, early maturing, late maturing, mature and spent. The development of oocytes indicated five phases: Chromatin-nucleolus (phase I), initial perinucleolar (phase II), final perinuclear (phase II), formation of vitelline vesicle or yolk (phase III), vitellogenic (phase IV) and complete vitellogenesis (phase V). The species has a prolonged spawning period, with two peaks coinciding with the rainy season.