Queen Formation Research Articles

Caste-specific expressions and diverse roles of takeout genes in the termite Reticulitermes speratus

Acquisition of novel functions caused by gene duplication may be important for termite social evolution. To clarify this possibility, additional evidence is needed. An important example is takeout, encoding juvenile hormone binding protein. We identified 25 takeouts in the termite Reticulitermes speratus genome. RNA-seq revealed that many genes were highly expressed in specific castes. Two novel paralogs (RsTO1, RsTO2) were tandemly aligned in the same scaffold. Real-time qPCR indicated that RsTO1 and RsTO2 were highly expressed in queens and soldiers, respectively. Moreover, the highest RsTO1 expression was observed in alates during queen formation. These patterns were different from vitellogenins, encoding egg-yolk precursors, which were highly expressed in queens than alates. In situ hybridization showed that RsTO1 mRNA was localized in the alate-frontal gland, indicating that RsTO1 binds with secretions probably used for the defence during swarming flight. In contrast, increased RsTO2 expression was observed approximately 1 week after soldier differentiation. Expression patterns of geranylgeranyl diphosphate synthase, whose product functions in the terpenoid synthesis, were similar to RsTO2 expression. In situ hybridization indicated RsTO2-specific mRNA signals in the soldier-frontal gland. RsTO2 may interact with terpenoids, with a soldier-specific defensive function. It may provide additional evidence for functionalization after gene duplication in termites.

LIDAR-based characterization and conservation of the first theropod dinosaur trackways from Arkansas, USA.

LIDAR-based analyses of the first theropod dinosaur trackways known from the state of Arkansas, USA are reported. The trackways were found on a limestone bedding plane in the Albian De Queen Formation in an active gypsum quarry. Because limited access precluded thorough field study, fieldwork focused on preserving the entire site digitally with ground-based LIDAR, and detailed measurements were later taken digitally from point cloud data. The site contains eight tridactyl trackways associated with sauropod trackways and numerous isolated tracks. Although there appear to be two different tridactyl morphotypes, we show that the tracks are all likely from a single species of trackmaker. We apply a simple method of estimating substrate consistency by comparing the differences between true track dimensions and apparent track dimensions. The tridactyl tracks at the southern end of the site are preserved with significantly greater differences in true vs. apparent dimensions and are shallower than the rest of the tridactyl tracks at the site, which we interpret as the result of outward expansion of the soft tissues of the foot upon contact with a firm substrate. We interpret the firm substrate as having high bulk density and high shear strength, which also explain associated manus-only sauropod tracks. We show that the tridactyl tracks are likely from theropod trackmakers and that footprint lengths, trackway paces, stride lengths, and pace angulations of the De Queen trackways are statistically indistinguishable from equivalent measurements of theropod trackways in the Glen Rose Formation. The Glen Rose tracks are attributed to the large-bodied theropod, Acrocanthosaurus and we likewise attribute the De Queen tracks to Acrocanthosaurus, which is known from skeletal remains in temporally equivalent units and from the mine itself.

The use of tracers to assess leakage from the sequestration of CO 2 in a depleted oil reservoir, New Mexico, USA

Geological sequestration of CO 2 in depleted oil reservoirs is a potentially useful strategy for greenhouse gas management and can be combined with enhanced oil recovery. Development of methods to estimate CO 2 leakage rates is essential to assure that storage objectives are being met at sequestration facilities. Perfluorocarbon tracers (PFTs) were added as three 12 h slugs at about one week intervals during the injection of 2090 tons of CO 2 into the West Pearl Queen (WPQ) depleted oil formation, sequestration pilot study site located in SE New Mexico. The CO 2 was injected into the Permian Queen Formation. Leakage was monitored in soil–gas using a matrix of 40 capillary adsorbent tubes (CATs) left in the soil for periods ranging from days to months. The tracers, perfluoro-1,2-dimethylcyclohexane (PDCH), perfluorotrimethylcyclohexane (PTCH) and perfluorodimethylcyclobutane (PDCB), were analyzed using thermal desorption, and gas chromatography with electron capture detection. Monitoring was designed to look for immediate leakage, such as at the injection well bore and at nearby wells, and to develop the technology to estimate overall CO 2 leak rates based on the use of PFTs. Tracers were detected in soil–gas at the monitoring sites 50 m from the injection well within days of injection. Tracers continued to escape over the following years. Leakage appears to have emanated from the vicinity of the injection well in a radial pattern to about 100 m and in directional patterns to 300 m. Leakage rates were estimated for the 3 tracers from each of the 4 sets of CATs in place following the start of CO 2 injection. Leakage was fairly uniform during this period. As a first approximation, the CO 2 leak rate was estimated at about 0.0085% of the total CO 2 sequestered per annum.

Using artificial intelligence to predict permeability from petrographic data

Petrographic data collected during thin section analysis can be invaluable for understanding the factors that control permeability distribution. Reliable prediction of permeability is important for reservoir characterization. The petrographic elements (mineralogy, porosity types, cements and clays, and pore morphology) interact with each other uniquely to generate a specific permeability distribution. It is difficult to quantify accurately this interaction and its consequent effect on permeability, emphasizing the non-linear nature of the process. To capture these non-linear interactions, neural networks were used to predict permeability from petrographic data. The neural net was used as a multivariate correlative tool because of its ability to learn the non-linear relationships between multiple input and output variables. The study was conducted on the upper Queen formation called the Shattuck Member (Permian age). The Shattuck Member is composed of very fine-grained arkosic sandstone. The core samples were available from the Sulimar Queen and South Lucky Lake fields located in Chaves County, New Mexico. Nineteen petrographic elements were collected for each permeability value using a combined minipermeameter–petrographic technique. In order to reduce noise and overfitting the permeability model, these petrographic elements were screened, and their control (ranking) with respect to permeability was determined using fuzzy logic. Since the fuzzy logic algorithm provides unbiased ranking, it was used to reduce the dimensionality of the input variables. Based on the fuzzy logic ranking, only the most influential petrographic elements were selected as inputs for permeability prediction. The neural net was trained and tested using data from Well 1–16 in the Sulimar Queen field. Relying on the ranking obtained from the fuzzy logic analysis, the net was trained using the most influential three, five, and ten petrographic elements. A fast algorithm (the scaled conjugate gradient method) was used to optimize the network weight matrix. The net was then successfully used to predict the permeability in the nearby South Lucky Lake field, also in the Shattuck Member. This study underscored various important aspects of using neural networks as non-linear estimators. The neural network learnt the complex relationships between petrographic control and permeability. By predicting permeability in a remotely-located, yet geologically similar field, the generalizing capability of the neural network was also demonstrated. In old fields, where conventional petrographic analysis was routine, this technique may be used to supplement core permeability estimates.

Abstract: Facies and depositional environments of the Permian Queen Formation, Howard Glasscock Field, Glasscock and Sterling Counties, Texas

Abstract: Facies and depositional environments of the Permian Queen Formation, Howard Glasscock Field, Glasscock and Sterling Counties, Texas

Fluvial and Deltaic Facies in the Queen Formation, Permian Basin of Texas and New Mexico: An Overview

Fluvial and Deltaic Facies in the Queen Formation, Permian Basin of Texas and New Mexico: An Overview

Depositional Environment and Stratigraphy of the Queen Formation in the North Ward-Estes Field, Permian Basin

Depositional Environment and Stratigraphy of the Queen Formation in the North Ward-Estes Field, Permian Basin

Fluvial and Deltaic Facies and Environments of the Late Permian Back-Reef Shelves of the Permian Basin of Texas and New Mexico

The Artesia Group is a sequence of carbonates, evaporites, and clastics that was deposited across the back-reef shelves of the Permian Basin during late Permian time. There has been some controversy over the depositional environments of the clastic members of the Artesia Group and the role of sea level fluctuations in their accumulation. However, the results of a regional core study of the Queen Formation of the Artesia Group indicate that they were largely deposited in desert fluvial and deltaic environments during low-stands of sea level. Three fluvial-deltaic facies are recognized within the clastic members of the Queen. The first consists of medium to very find sandstones and silty sandstones with cross-beds, ripple cross-laminae, and planar and wavy laminae. This facies forms wavy sheets that thicken and thin along linear trends, and was deposited in sandy braided streams. The second facies consists of very find to fine sandstones, silty sandstones, and siltstones with ripple cross-laminae, planar and wavy laminae, cross-beds, clay drapes and pedogenetic cutans, as well as siltstones and silty mudstones with haloturbation structures and evaporite nodules. This facies forms thick planar sheets, and was deposited in fluvial sandflats and adjacent fluvial-dominated continental sabkhas. The third facies consists ofmore » cyclic deposits of haloturbated silty mudstones that grade into siltstones and very fine sandstones with crossbeds, planar and wavy laminae, haloturbation structures and evaporite nodules. Each cycle forms a lobate body that is bounded by carbonates or evaporites and which was deposited in sheet deltas that formed along the landward margins of a back-reef lagoon.« less

Pedogenetic Features in Sandstones of the Queen Formation, Permian Basin

Pedogenetic Features in Sandstones of the Queen Formation, Permian Basin

Depositional Environments and Reservoir Properties of the Upper Queen Formation, Concho Bluff and Concho Bluff North Fields, Midland Basin, Texas

The upper Queen Formation (Upper Permian) in Concho Bluff and Concho Bluff North fields (Crane, Upton, and Ector counties, Texas) consists of four thick (6-11 m) clastic members separated by evaporite members, and contains several major sandstone reservoirs. A study of cores and logs from the upper Queen was done to determine its depositional environments and the properties of its sandstone reservoirs. Four facies are present in the upper Queen. Facies 1 consists of planar- and wavy-laminated fine and very fine sandstones and silty sandstones deposited in fluvial sandflats and delta-plains. Facies 2 consists of wavy-laminated siltstones and haloturbated mudstones with anhydrite nodules deposited in subaqueous prodelta environments and subaerial saline mudflats. Facies 3 consists of well-sorted fine to very fine sandstones with horizontal and inclined planar laminae deposited in eolian sand sheets. Facies 4 consists of massive to laminated halite and anhydrite deposited in hypersaline playas. The vertical sequence of these facies indicates that the upper Queen was deposited during four cycles of fan-delta progradation into and retreat from coastal-plain playas during a sea level lowstand in the Midland basin. The sandstones of the fluvial sandflat and eolian sand-sheet facies constitute the reservoirs of the upper Queen in themore » fields. The average cumulative thickness of these facies is 8 m, and the fields average 16% porosity and 40-50 md of permeability. The remaining facies are all nonproductive with averagge porosities of less than 10% and average permeabilities of less than 1 md.« less

Diagenesis of the Sandflat and Mudflat Facies of the Upper Queen Formation, Midland Basin, Texas

The upper Queen Formation (Permian, Guadalupian) of the Midland basin, Texas, consists of cyclically interbedded clastics and evaporites that were deposited in a fluvial-dominated continental sabkha environment. Fluvial sandflat deposits, consisting of thin units (0.2-5.0 m) of very fine grained arkosic sandstones constitute reservoir horizons, whereas 0.1-1.3 m thick units of coarse siltstones and evaporites of playa-mudflat deposits are nonproductive. This study addresses the diagenetic histories of the reservoir and nonreservoir clastics. The primary porosity of the clastics was first reduced by pore-filling hematitic smectite clay, anhydrite, and dolomite during an early diagenetic phase. Subsequent dissolution of the anhydrite and dolomite by acidic pore-waters created high porosities (mean = 15%) and permeabilities (mean = 70 md) in the sandflat deposits, porosities which were only slightly occluded by later dissolution and reprecipitation of grain-lining smectite. Pore-water movement and subsequent hydrocarbon migration were both controlled by the coarser grain size and lower clay-matrix and silt content of these sandflat deposits. In contrast, the finer grain size and higher clay-matrix and silt content prevented similar dissolution of cements within the mudflat facies, which have significantly lower porosities (mean{lt}10%) and permeabilities (mean{lt}0.1 md). Fluids and gases used in enhanced recovery techniques will follow pathwaysmore » created by dissolution of anhydrite and dolomite cements within the sandflat facies. However, caution must be used with fluids that can cause swelling of the grain-lining smectite.« less

Depositional and Diagenetic Controls on Porosity Permeability and Oil Production in McFarland/Magutex (Queen) Reservoirs, Andrews County, West Texas

The McFarland/Magutex Queen reservoir complex lies along the northeastern edge of the Central basin platform in the west Texas Permian basin and produces oil from the Permian Queen Formation. Current production from this complex totals 42 million stock-tank barrels (MMSTB) of an estimated 219 MMSTB of original oil in place, with an estimated 90 MMSTB of remaining mobile oil (RMO). The gross pay interval contains two parasequences consisting of progradational, 30-ft-thick, upward-shoaling facies packages. Facies include shoreface, mixed tidal channel and intertidal flat, and supratidal. Elongate shoreface facies are characterized by poorly consolidated, massive to thinly laminated sandstones. The supratidal facies, which act as permeability barriers, are characterized by algal-laminated dolostone and nodular, laminated, and massive anhydrite containing halite and gypsum pseudomorphs. Highest production and the largest amount of the 90 MMSTB of RMO is associated with the shoreface and tidal-channel facies. Bulk pore volume storage capacity and permeability are also highest within these two facies. Sandstones are arkosic, containing anhydrite and dolomite cements. Accessory minerals are clays, authigenic feldspar, and dolomite. Three main pore types are recognized: interparticle, moldic and intraconstituent, and micropores. Moldic and intraconstituent porosity is associated with leached feldspars and anhydrite cement dissolution. Microporosity is associatedmore » with syndepositional, grain-coating corrensite, dissolution-enhanced feldspar cleavage planes, and authigenic multifaceted dolomite. Microporosity derived from clays and dolomite is formed preferentially in tidal-channel and intertidal flat facies.« less

Formation of Clastic Reservoirs in the Queen Formation of the West Midland Basin of Texas: ABSTRACT

Formation of Clastic Reservoirs in the Queen Formation of the West Midland Basin of Texas: ABSTRACT

Shattuck Member of Queen Formation (Permian), Northwest Shelf, Permian Basin: Eolian Sandstone Deposited During a Lowstand of Sea Level: ABSTRACT

The Queen Formation is a sequence of carbonates, evaporites, and sandstones of Permian (Guadalupian) age that is found across the subsurface Northwest shelf of the Permian basin. The formation is a major reservoir for oil and gas, and one of its producing zones is a thick sandstone (equivalent to the Shattuck sandstone) that defines the top of the Queen. Studies of logs and cores of the Shattuck from Caprock and Central Corbin fields (Chaves and Lea Counties, New Mexico) were undertaken to determine its sedimentary history. The Shattuck is a wedge-planar sand body that thickens downdip (Caprock to Corbin) from 6 to 19 m. It generally has sharp (in some places clearly erosive) contacts with dolomite and anhydrite that lie above and below it. The Shattuck is composed of well-sorted arkosic to subarkosic silty sand, and it contains the following sedimentary structures (in order of decreasing abundance): (1) high-angle cross-bedding, (2) planar wind-rippled laminae, (3) wavy and discontinuous adhesion laminae, (4) wavy and lenticular-bedded water ripples, and (5) contorted and massive beds with small nodules of anhydrite. The cross-bedded and wind-rippled sandstones are generally reservoirs for oil and gas; the remaining lithologies are not reservoirs. The Shattuck was deposited inmore » continental eolian environments during a lowstand of sea level. This lowstand exposed highstand marine and shoaling sediments (carbonates and evaporites) beneath the Shattuck to subaerial erosion and weathering, and they were soon buried by windblown sand. The sand accumulated in desert dunes (cross-bedded sandstone), sand sheets (erges) that were alternately dry (planar-laminated sandstone) and wet (adhesion laminae, water ripples), and sabkhas (anhydritic sandstone). Deposition of the Shattuck was terminated by a sudden rise in sea level and the return of marine depositional environments.« less

Application of Sequence Stratigraphy to Permian Carbonates and Evaporites, McElroy Field, Central Basin Platform, Texas: ABSTRACT

The McElroy field in west Texas is part of a series of Permian subsurface carbonate reservoirs fringing the eastern margin of the Central Basin platform. Traditionally, these reservoirs have been subdivided into three stratigraphic units: San Andres Formation, Grayburg Formation, and Queen Formation. The San Andres and Grayburg Formations apparently form shallowing-upward cycles capped by intertidal or low-supratidal facies. Oil production occurs mainly from the Grayburg Formation. The Queen Formation consists largely of bedded sulfates and siltstones, and forms the reservoir seal. Applying the concept of sequence stratigraphy to wireline logs and core data refines the previous stratigraphic and geologic interpretations. (1) The Grayburg Formation consists of three internal cycles. (2) Laterally equivalent types of microfacies are similar but not identical during transgression and regression. (3) A paleo-shoreline was present near the eastern margin of the field before the end of Grayburg deposition. (4) Syndepositional downfaulting of the eastern part of the field by several meters occurred during Grayburg deposition. (5) Downfaulting of the eastern part of the field by several tens of meters occurred after Queen deposition. These findings may help interpret reservoir diagenesis. In particular, pervasive dolomitization and emplacement of sulfates (mainly gypsum and anhydrites) may be relatedmore » to the internal cyclicity or the faulting events.« less

Sedimentation of Shelf Sandstones in Queen Formation, McFarland and Means Fields, Central Basin Platform of Permian Basin: ABSTRACT

The Queen Formation is a sequence of carbonates, evaporites, and sandstones of Permian (Guadalupian) age that is found across the subsurface of the Central Basin platform of the Permian basin. The formation is a major hydrocarbon reservoir in this region, and its primary reservoir facies are porous shelf sandstones and dolomites. Cores and well logs from McFarland and Means fields (on the northwest margin of the Central Basin platform) were examined to determine the sedimentary history of the shelf sandstones.

McElroy Field, Permian Basin, West Texas: Cyclic Sequence Dolomite Reservoir of Central Basin Platform: ABSTRACT

The McElroy field, located in Crane and Upton Countries of west Texas, is one of several carbonate reservoirs developed along the eastern margin of the Central Basin platform. The reservoir rock at McElroy consists of Permian System (Guadalupian Series) dolomite of the Grayburg Formation. The Grayburg dolomite and the underlying San Andres Formation were formed as shallowing-upward carbonate sequences. The carbonate facies are overlain by the Queen Formation, an evaporite-dominated unit that serves as the reservoir seal. The Grayburg Formation carbonates consist of dolomitized lime mudstones, wackestones, pelletal and skeletal packstones, and ooid grainstones deposited in subtidal to supratidal environments. Facies prograde eastward toward the Midland basin, suggesting relative sea level lowering or progressive shallowing. The westward limit of the McElroy field is determined by pinch out of reservoir carbonates that interfinger with supratidal nodular and bedded anhydrite. The reservoir petrophysical characteristics are defined by diagenetic overprinting on primary carbonate depositional fabrics. The principal diagenetic processes include dolomitization, anhydrite occlusion of primary porosity, and leaching. McElroy, which was discovered in 1926, produces approximately 13,500 BOPD. This Chevron-operated field has 2.2 billion bbl of oil in place; 329 million bbl have been produced from nearly 1,600 wells. The field is currentlymore » under waterflood and is being evaluated for potential CO/sub 2/ injection.« less

Provenance, Diagenesis, and Reservoir Characteristics of Shattuck Member of Queen Formation (Permian), Northwest Shelf, Permian Basin: ABSTRACT

The Shattuck Member of the Queen Formation forms important stratigraphic traps for oil and gas on the Northwest shelf of the Permian basin. The Shattuck is a wedge-planar body of well-sorted silty sandstone and has a detrital composition of 70-85% quartz, 15-30% feldspar, and traces (less than 2%) of mica and opaque iron-oxide grains. Generally, the quartz grains are rounded to subrounded and the feldspar grains (which are mostly microcline) are partly weathered and dissolved. The detrital composition of the Shattuck reflects its partial derivation from deeply weathered granitic rocks in the Pedernales Mountains. The texture and roundness of the quartz grains reflect the effects of transport by the wind, which deposited the Shattuck on the Northwest shelf during a lowstand of sea level. The reservoir lithology within the Shattuck is a pale yellow-brown sandstone that was deposited in desert dunes and dry sand sheets. This sand was cemented by anhydrite, dolomite, and authigenic clay during a shallow (precompaction) diagenetic phase, but the cement was later partly dissolved. The reservoir lithology presently has 2-15% porosity and permeabilities between 30 and 500 md. The nonreservoir lithology is a reddish-brown sandstone that was deposited in wet eolian sand sheets and contains detritalmore » hematitic clay (as matrix and within laminae) and hematite-coated detrital grains of possible pedogenetic origins. This sand was completely cemented by anhydrite, dolomite, and traces of authigenic clay during a shallow diagenetic phase, but the cements did not later dissolve to form secondary porosity. The nonreservoir lithology presently has less than 1% porosity and less than 10 md permeability.« less

Eolian and Fluvial Facies in Sandstones of Queen Formation, Permian Basin, Texas: ABSTRACT

Eolian and Fluvial Facies in Sandstones of Queen Formation, Permian Basin, Texas: ABSTRACT

Petrography and Diagenesis of Reservoir and Non-Reservoir Sandstones in Shattuck Member of Queen Formation, Northwest Shelf of Permian Basin: ABSTRACT

The Shattuck Member is a thick (6-20 m) sandstone that defines the top of the Queen Formation (Permian, Guadalupian) and is a major hydrocarbon reservoir on the Northwestern shelf of the Permian basin. The Shattuck was deposited in desert dune and interdune, dry and wet sand sheet, and sandy sabkha environments during a lowstand of sea level. The desert dune, interdune, and dry sand sheet deposits constitute the producing horizons in the Shattuck, whereas the wet sand sheet and sabkha deposits are generally non-productive. The purposes of this study are to examine the petrographic characteristics of the producing and non-producing horizons with petrographic and scanning electron microscopes, and to determine their provenance and diagenetic history.