Trap Reservoirs Research Articles

The pre-Jurassic Meng-Shaan paleochannel and its control on the accumulation model of Yan 10 reservoir in Central Ordos Basin

In the setting of the increasing density of exploration wells, and the decreasing scale and increasing difficulty of discovering Jurassic paleogeomorphology reservoirs, it is urgent to deepen the fine depiction of pre-Jurassic paleogeomorphology features and to analyze their controlling effect on reservoirs. Based on abundant logging data combined with indoor microscopic observation and experimental testing, the paper applies the theory of reservoir configuration analysis for the first time to the single-channel period division of the pre-Jurassic Meng-Shaan paleochannel which deposited with the braided channel sand bodies. Meanwhile, it reveals the controlling effect of hydrocarbon accumulation and the distribution characteristics of the Yan 101 reservoir as ' paleogeomorphology and sedimentary facies combination' to determine the type, 'migration channel' to determine the distributing range, and 'low-amplitude structure' to determine the trap in the study area, and also the reservoir accumulation modes in different channel ranges have established. In conclusion, the single-channel boundary of the Meng-Shaan paleochannel in different periods controls the path of oil and gas migration, thus controlling the distribution range and reservoir type of the Yan 10 reservoir. Moreover, depending on the production data we derived that it should prefer the composite trap reservoir of the Fuxian period and the Yan 102 period, as well as the structural reservoir on the periphery of the Yan 102 period single-channel for the further exploration of the Yan 10 paleogeomorphology reservoirs within the development range of the Meng-Shaan ancient river. In particular, the lithologic trap reservoirs within the Fuxian period channel and the Meng-Shaan main channel, such as the reservoirs of the 'Source' of the secondary channel type and the paleochannel type, which could as a replacement accumulation model for increasing reserves and production.

Deployment and Fact Analysis of the In2Care® Mosquito Trap, A Novel Tool for Controlling Invasive Aedes Species.

During April-October 2019, the West Valley Mosquito and Vector Control District (Ontario, CA) deployed large numbers of In2Care® mosquito traps in a preliminary study to evaluate the trap's potential effectiveness at controlling invasive Aedes aegypti (L.) and Ae. albopictus (Skuse) in 6 cities of San Bernardino County, CA. The trap was used to attract ovipositing females, expose them to the juvenile hormone mimic pyriproxyfen and the entomopathogenic fungus Beauveria bassiana, and autodisseminate pyriproxyfen to other water sources prior to their death from fungal infection. The trap attracted Ae. aegypti and Culex quinquefasciatus, with the latter species predominating at much higher larval densities in the trap reservoirs. Field-collected larvae and pupae from the trap reservoirs showed complete adult emergence inhibition. Furthermore, the trap reservoirs retained high levels of residual larvicidal, pupicidal, and emergence inhibition activity after they were retrieved from the field, as indicated by laboratory bioassays against laboratory colony of Cx. quinquefasciatus. Results of this study support more detailed quantitative local evaluations on trap efficacy to measure the impact of the In2Care mosquito trap on wild invasive Aedes and Culex populations in future mosquito control efforts.

Lunar polar water resource exploration – Examination of the lunar cold trap reservoir system model and introduction of play-based exploration (PBE) techniques

Driven by a need to find low-cost energy solutions to meet anticipated demands arising from increased robotic and human cislunar activities, the extraction and utilization of naturally occurring volatiles found on the lunar surface is an area of growing interest to both the private and public space sectors. The use of hydrogen and oxygen extracted from accumulations of water is viewed as particularly promising. Several lines of evidence point to the presence of water, possibly in the form of water ice, stored within cold trap reservoirs in the permanently shadowed regions (PSRs) of the northern and southern poles of the Moon. The type and spatial resolution of available datasets however prevent evaluation of resource potential on a scale relevant to address geological uncertainties and assess the technological and economic feasibility of water resource extraction for use by an in-space market. Surface field exploration is required to reduce investment risk; however the success of resource exploration activities will depend on the selection of appropriate exploration methods. To address this we introduce the application of play-based exploration (PBE) techniques, a resource exploration approach commonly used by the terrestrial petroleum and geothermal energy industries to direct decision making regarding high-risk ventures. Applied to the Moon this method seeks to identify locations where exploration activities are most likely to encounter an economically/commercially viable quantity of water guided by the geological concepts of delivery, trapping, and storage of water molecules within a reservoir. In this study we examine the critical geological uncertainties in the reservoir system model and provide recommendations for resource exploration approach, data collection, and analysis techniques.

Description technology for unconformity trap reservoirs with strong seismic reflections: a case of the Mesozoic unconformity reservoir in Changdi area, Jiyang depression

Description technology for unconformity trap reservoirs with strong seismic reflections: a case of the Mesozoic unconformity reservoir in Changdi area, Jiyang depression

Development of petroleum geology in China: Discussion on continuous petroleum accumulation

Petroleum exploration targets are extending gradually from the single conventional trap reservoirs to the large-scale unconventional continuous accumulations. Oil and gas reservoirs have been divided into two types based on the trapping mechanism and distribution of oil and gas: conventional single-trap reservoirs, such as the Daqing oil field in Songliao Basin and the Kela-2 gas field in Tarim Basin; and unconventional continuous petroleum accumulation, such as Upper Paleozoic tight gas and Mesozoic tight oil in Ordos Basin, and Upper Triassic tight gas in Sichuan Basin. Two typical geologic characteristics of continuous petroleum accumulation involve: (1) coexisting source and reservoir, petroleum pervasive throughout a large area tight reservoirs, and no obvious traps or well-defined water-oil and gas contracts; (2) non-buoyancy accumulation, continuous petroleum charge, and no significant influence by buoyancy. Continuous petroleum accumulation generally have nm-scale pore throats, and the diameters range of 10-500 nm. The geometry and connectivity of these pore throats has significant impact on the migration and distribution of oil and gas in continuous petroleum accumulation. China has numerous continuous petroleum accumulation containing various petroleum deposits, and the exploration of continuous resources is very promising. Unconventional petroleum geology will become an important new subject in petroleum geology in future, and the nano-technology will function greatly on research, exploration and development of the hydrocarbon accumulation in nanopore-throats.

Air Removal Efficiency of a Venous Bubble Trap in a Minimal Extracorporeal Circuit During Coronary Artery Bypass Grafting

The use of minimized extracorporeal circuits (MECC) in cardiac surgery is expanding. These circuits eliminate volume storage and bubble trap reservoirs to minimize the circuit. However, this may increase the risk of gaseous micro emboli (GME). To reduce this risk, a venous bubble trap was designed. This study was performed to evaluate if incorporation of a venous bubble trap in a MECC system as compared to our standard minimized extracorporeal circuit without venous bubble trap reduces gaseous micro emboli during cardiopulmonary bypass (CPB). Forty patients were randomly assigned to be perfused either with or without an integrated venous bubble trap. After preliminary evaluation of the data of 23 patients, the study was terminated prior to study completion. The quantity and volume of GME were significantly lower in patients perfused with a venous bubble trap compared to patients perfused without a venous bubble trap. The present study demonstrates that a MECC system with a venous bubble trap significantly reduces the volume of GME and strongly reduces the quantity of large GME (>500 µm). Therefore, the use of a venous bubble trap in a MECC system is warranted.

Quantitative prediction of the oil-bearing height of Tertiary stratigraphic reservoirs in Jiyang Depression

Abstract The Tertiary stratigraphic reservoirs in Jiyang Depression are characterized by small buried-depth, long distance of trap from source, low oil-bearing height and poor oil physical property. Oil-bearing height is mainly determined by four factors: expulsion rate of source rock, migration distance, dip angle of carrier bed and capillary resistance force. Of these four factors, the expulsion rate can be expressed by the pressure factor gradient of source rock, the migration distance can be expressed by the horizontal and vertical distances between trap and source, and the capillary resistance force in carrier beds can be expressed by the capillary pressure in trap reservoirs. From the statistics of 62 stratigraphic reservoirs, oil-bearing height is in positive correlation with pressure factor gradient and dip angle of carrier bed and in negative correlation with horizontal and vertical distances between trap and source and capillary resistance force. On the basis of relations analysis between oil-bearing height and single factors, the multi-parameter match expression for the stratigraphic reservoir oil-bearing height has been established through multiple regressions. The application results show that the predicted value from match expression matches well with the true value. The expression can be used for the prediction of oil-bearing height of Tertiary stratigraphic reservoirs in Jiyang Depression.

Global importance of “continuous” petroleum reservoirs: Accumulation, distribution and evaluation

Abstract Based on distribution of oil and gas in the world, the connotation and characteristics of “continuous” petroleum reservoirs are elaborated in this paper. “Continuous” petroleum reservoirs refer to unconventional trap reservoirs existing in a large-scale unconventional reservoir system, and the distribution of oil and gas is continuous. The main geological characteristics of “continuous” petroleum reservoirs are as follows: located in the center and slope of a basin, large-scale distribution and rich locally; mainly of large-scale unconventional reservoirs; traps have no clear boundaries; mainly of self-generating and self-preserving; mainly of primary migration; accumulated by diffusion and buoyancy is limited; non-Darcy flow; poor oil-water differentiation and different saturation; oil, water and gas coexist and have no common interface and pressure system; resources abundance is low and reserves are calculated by well-control region; the mining technologies are special and tailored techniques are required. In this paper are discussed the cause of deep-water “sandy debris flow” and a few examples on “continuous” reservoirs, the shallow-water delta low or ultra-low porosity and permeability reservoirs, coal-bed methane and shale-cracked reservoirs and so on.

Application of Integrative Geophysical Methods To Predicting Sedimentary Facies of Marine Residual Basins in Middle Guangxi Province, China

AbstractThe sedimentary facies study is one of the key procedures in exploration of subtle reservoirs in basins, of which a prerequisite is effective identification of its structural, lithologic or lithofacies differences through integrated usage of geophysical methods. Based on geophysical data, including gravity, aeromagnetic and seismic data, this paper describes the density distribution characteristics of marine strata in middle Guangxi province, South China, and predicts the regularities of lithofacies and sedimentary facies changes in terms of potential field forward stripping and profile forward/inverse fitting. It is revealed that transversal lithologic and lithofacies changes exist in the marine strata of mid‐ and lower‐Devonian series of the area. The platform zones in the northwest and southeast of the area have high gravity anomalies and high fitting rock density. The “X”‐shaped platform‐marginal facies zone in the middle is characterized by irregular gravity anomalies and a large variation range of fitted rock density. And the platform‐trough facies zone in the east exhibits low gravity anomalies as well as low fitted rock density. Predicting sedimentary facies through integrative geophysical methods offers a new approach for exploration of lithologic trap reservoirs and bioherm reservoirs in basins. This method has been preliminarily proved, and needs further improvements and applications.

Paleostructural geomorphology of the Paleozoic central uplift belt and its constraint on the development of depositional facies in the Tarim Basin

Inclined eastward and consisting of the Hetianhe, Hetianhedong, Tazhong paleouplifts and Bachu paleoslope, the central paleouplift belt in the Tarim Basin was a large composite paleouplift and paleoslope belt with complicated palaeogeomorphic features during the Middle to early Late Ordovician. A number of paleostructural geomorphic elements have been identified in the paleouplift belt and surrounding areas, such as the high uplift belts, the faulted uplift platforms, the marginal slopes and slope break zones flanking the paleouplift belt, the surrounding shelf slopes or low relief ramps, the shelf slope break zones and deep basin plains. They exerted great influence on the development of paleogeography of the basin. The marginal slopes and slope break zones flanking the uplift belt constrained the formation and deposition of the high-energy facies including reefal and shoal deposits during the Late Ordovician, which comprise the major reservoirs of the Lower Paleozoic in the basin. Toward the end of the Ordovician, the Tazhong paleouplift hinged westward and became a westward-dipped nose as the southeastern margin of the basin was strongly compressed and uplifted. The tectono-paleogeomorphic framework of the central northern basin during the Early Silurian and the Late Devonian to Early Carboniferous changed remarkably in topography from the initial low in east and high in west to high in northeast and low in southwest. The major paleogeomorphic elements developed in these periods included the strong eroded uplift high, the uplift marginal slope, the gentle ramp of the depression margin and the depression belt. The sandstones of the lowstand and the early transgressive systems tracts were deposited along the uplift marginal slopes and the gentle ramps of the depressions comprise the prolific reservoirs in the basin. The study indicates that the distribution patterns of the unconformities within the basin are closely related to the paleogeomorphic features and evolution of the paleouplift belt. From the high uplift belt to the depression, we found the composed unconformity belts at the high uplift, the truncated and onlap triangular unconformity belts along the uplift marginal slopes, the minor angular unconformity or discontinuity belts along the transitional zones from the uplift marginal slopes to depression and the conformity belt in the central depression. The truncated and the onlap triangular unconformity belts are the favorable zones for the formation of stratigraphic trap reservoirs.

Hydrocarbon accumulation in deep fluid modified carbonate rock in the Tarim Basin

The activities of deep fluid are regionalized in the Tarim Basin. By analyzing the REE in core samples and crude oil, carbon isotope of carbon dioxide and inclusion temperature measurement in the west of the Tazhong Uplift in the western Tarim Basin, all the evidence confirms the existence of deep fluid. The deep fluid below the basin floor moved up into the basin through discordogenic fault and volcanicity to cause corrosion and metasomatosis of carbonate rock by exchange of matter and energy. The pore structure and permeability of the carbonate reservoirs were improved, making the carbonate reservoirs an excellent type of deeply buried modification. The fluorite ore belts discovered along the large fault and the volcanic area in the west of the Tazhong Uplift are the outcome of deep fluid action. Such carbonate reservoirs are the main type of reservoirs in the Tazhong 45 oilfield. The carbonate reservoirs in well YM 7 are improved obviously by thermal fluid dolomitization. The origin and territory of deep fluid are associated with the discordogenic fault and volcanicity in the basin. The discordogenic fault and volcanic area may be the pointer of looking for the deep fluid modified reservoirs. The primary characteristics of hydrocarbon accumulation in deep fluid reconstructed carbonate rock are summarized as accumulation near the large fault and volcano passage, late-period hydrocarbon accumulation after volcanic activity, and subtle trap reservoirs controlled by lithology.

Reservoir Description and Future Development Plans for the Unam/Mfem Fields OML 67, Nigeria: ABSTRACT

The Unam/Mfem fields, which are currently produced from three platforms, are, located 25 km offshore (southeastern Nigeria) in water depths of 60 feet to 100 feet. Over 100 MMBO have been produced to date from both unconformity bounded and fault trap reservoirs in the Upper and Middle Biafra Sands. These structural and stratigraphic geometries define at least eleven different reservoirs that are not interconnected. STOIIP for all eleven reservoirs is estimated to exceed 900 MMBO based on a recently completed reservoir characterization study. A two year reservoir description study followed the acquisition of a 1991 3-D seismic survey and resulted in the drilling of six successful wells and two sidetracks. A 3-D model of reservoir geometries and fluid flow properties was generated by integrating geologic, geophysical, and reservoir engineering data. These diverse data sets were interpreted using a combination of workstations, software packages, and displays that included Landmark, IREX, wireline log and seismic correlation charts. A detailed stratigraphic zonation scheme with 28 zones was defined and correlated field wide and subregionally to build the reservoir framework. Twenty seismic horizons were created. More than 300 critical compute, generated grids were then used to calculate STOIIP volumes. This study led to themore » identification of new pay zones along with a much better understanding of the spatial distribution of all pays within the fields. A revised exploitation strategy has subsequently been proposed which calls for 5 new platforms and the drilling of 21 additional wells over the next few years.« less

Styles of heterogeneity in dolomitized platform carbonate reservoirs: Examples from the central basin platform of the permian basin, southwestern USA

The Permian Basin of West Texas and southeastern New Mexico, southwestern U.S.A., is the premiere oil basin of the United States. At discovery, reservoiors in this prolific province contained more than 100 billion barrels of oil, almost a quarter of all the discovered in the U.S. Almost half of this resource (43%) was contained in a single reservoir type, dolomitized platform carbonate. Dolomitized platform carbonates were deposited on shallow shelves fringing the basin and on a horst block, the Central Basin Platform, that divides the basin and separates sites of deep-water siliciclastic sedimentation in the adjacent subbasins. The Central Basin Platform hosts many large combined structural/stratigraphic trap reservoirs in dolomitized platform carbonates. These range in size up to four billion barrels of original oil in place. Integrated geoscience and engineering characterization of four of these fields; Dune, Emma, Penwell, and Taylor-Link, allows comparison of the styles and scales of heterogeneities that influence recovery in this reservoir type. Facies composition and architecture exert fundamental controls on paths of fluid movement during production. Principal facies are extensive, deep subtidal fusulinid wackestones that shoal upward into shallow-subtidal and intertidal packstones and grainstones in which the dominant productive facies are grainstone bars and shoals, and shorezone systems that are dissected by dip-oriented tidal systems. Rapid lateral facies changes together with highly cyclic shoaling sequences result in pronounced permeability variations both laterally and vertically in the section. Superimposed on the depositional framework is a multi-event diagenetic overprint. These carbonate reservoirs are thoroughly dolomitized and partly cemented by sulfates. A post-burial leaching event increased permeability in some parts of these rocks. Karst processes have a large affect on reservoir quality in the southern part of the Central Basin Platform. Even though these carbonate reservoirs have undergone substantial diagenetic modification depositional facies still exert the primary control on remaining, and in particular, mobile, oil saturation.

Geologic Aspects of Origin of Petroleum

Geologic Aspects of Origin of Petroleum

Classification of Petroleum Reservoirs

The classification presented in this study divides petroleum reservoirs into five major groups. A. Convex trap reservoirs B. Permeability trap reservoirs C. Pinch-out trap reservoirs F. Fault trap reservoirs G. Piercement trap reservoirs Trapping properties are found in the conditions of reservoir beds, as well as in the configuration of the structural environment in which reservoirs are located. The first set of trapping properties is defined by Trap Indicators and the second set by Environment Indicators. The individual traps which cause the various types of reservoirs result from the logical combinations of these indicators. The reservoir system is built up inductively and should serve as a tool in the search for petroleum.