Multiple Trophic Levels in Soft-Bottom Communities

In order to assess the general applicability of recent field experiments with predatory infauna, we searched the literature and found 48 well-documented cases of infaunal consumption by such predators. In 63 % of the cases detailed enough to make a determination, the predators ate other predators. Multiple trophic levels within the infauna are probably a common feature of many soft-bottom communities

STARR Progress Report

The State of Texas Advanced Resource Recovery program (STARR) has achieved its primary goal of boosting severance tax revenue for the State through research projects aimed at promoting the drilling of profitable oil and gas wells. Currently, the Bureau of Economic Geology (BEG) receives state funding to conduct research that aids oil and gas operators in either establishing new production or enhancing existing production across Texas. STARR operates under the mandate of being revenue neutral, meaning that the revenue generated from STARR projects must at least match the funds allocated by the Legislature. This progress report provides a detailed summary of the accomplishments of Project STARR over the past two years, from September 1, 2012, to August 31, 2014. According to the methodology approved by the State of Texas Comptroller's office, the credit attributed to the STARR program for the 2012—2014 biennium amounts to $140,766,560 (see table 1). With total income of$9 million over the current biennium, STARR demonstrates a positive revenue impact of 15.6. To date, the STARR program has concluded or is actively engaged in over 60 field (reservoir characterization) studies (see figs. 1 and 2). Figure 2 highlights 23 significant new reservoir characterization studies conducted during the 2012—2014 biennium. Additionally, STARR has initiated 8 new regional studies, encompassing areas such as the Eaglebine trend in southeastern Texas Gulf Coast, as well as the Cline Shale and Wolfcamp and Spraberry Formations in the Permian Basin of West Texas (see fig. 3). Furthermore, STARR includes eight supplementary program elements that complement the Oil and Gas Resources program. Each of these elements targets research relevant to critical economic opportunities or challenges in Texas concerning natural resources or geological conditions. These elements encompass geothermal resources, water-related issues affecting the Texas economy, mineral and earth resources, geological hazards, energy economics, baseline mapping for oil spill response, economic implications of environmental flows, and analysis of water-energy nexus issues.Bureau of Economic Geolog

Power frame

A rotor stage disposed within an annular fluid flowpath in a turbomachine is disclosed. The rotor stage includes outer and inner rings and a plurality of first and second airfoils. The outer and inner rings define flowpath surfaces for said flowpath. The first and second airfoils extend between the rings for transferring energy between the fluid and the rotor stage. At least one of the first airfoils surrounds means for transmitting energy across the flowpath

Rotating cowling

The invention concerns a cowling for aircraft propulsion systems of the counterrotating propeller type. The cowling includes a pair of mounting rings located fore and aft of a propeller array. Removable panels extend between the mounting rings and contain openings through which the propeller blades extend

Secondary Natural Gas Recovery: Targeted Technology Applications for Infield Reserve Growth: Case Studies Evaluating the Benefits of Secondary Gas Recovery, Onshore Gulf Coast, South Texas

Economic recovery of natural gas in reservoirs with near-tight to conventional porosity and permeability can be improved through geologically based infill-development strategies. Old gas fields may contain new infield reservoirs, incompletely drained reservoir compartments, untapped reservoir compartments, and bypassed reservoirs. These secondary resources may be identified by a combination of log evaluation and production and pressure analyses, and they are controlled by structural and stratigraphic heterogeneity. Many gas fields in the Gulf Coast may contain opportunities for identifying additional gas resources at modest costs. Remaining natural gas in these fields can be contacted either by recompleting existing wells that have bypassed reservoir compartments or by drilling strategically targeted infield wells. Exploration for new, untapped, or incompletely drained reservoir compartments or bypassed gas zones in old fields can be improved by using state-of-the-art formation evaluation tools and engineering, production, petrophysical, and geological analyses. The economics of developing and producing the secondary gas recovery (SGR) resource is evaluated for two producing properties in existing fields. The case I study area (North Mcfaddin field) had total operational and development costs (excluding royalties) of $0.58 per mcf, compared to total costs in case II (Agua Dulce field) of$0.83 per mcf. Future application of SGR concepts and technology to strategically targeted well locations and recompletions could further lower development costs.Bureau of Economic Geolog

Assessment of Gas Resources for Secondary Gas Recovery Technology

Unrecovered gas resources available through existing technology can be a significant source of reserve additions in maturely explored petroleum provinces. In this study, nonassociated and associated Texas reservoirs were analyzed for gas reserve growth potential. In the nonassociated fluvial Frio Brooks reservoir, infill drilling from 640 to 320 acres per well can potentially increase reserves by 15.7 percent of estimated ultimate recovery. Gas reserve additions may result from improved contact with isolated or partially isolated sandstones that are not effectively drained by conventional development practices. An additional 14.4 billion cubic feet (Bcf) of gas resources can be potentially recovered by strategic infill drilling down to 10-acre spacing in the Grayburg reservoirs of Dune field, one of many mature West Texas fields located on the Central Basin Platform. Infill wells strategically drilled in the Dune field grainstone facies are projected to be most cost-efficient and productive. Recoverable associated gas in selected plays is estimated to be from 3.4 trillion cubic feet (Tcf) to 5.8 Tcf. The greatest recovery potential for associated gas reserve growth in Texas is in carbonate reservoirs with complex facies architecture in the Permian Basin. Geologically based infill wells in areas of greatest reservoir heterogeneity can recover much of this unproduced gas resource.Bureau of Economic Geolog

Coordination of Geological and Engineering Research in Support of the Gulf Coast Co-Production Program

Complex and heterogeneous Hackberry reservoirs at Port Arthur field were deposited in a submarine canyon/fan setting. Conventional fieldwide hydrocarbon recovery efficiencies are low, but the potential for secondary gas recovery is high. Free gas remains trapped in uncontacted and untapped compartments at reservoir abandonment. The total fieldwide resource amounts to 13.9 Bcf. The probable and possible resource for a single infill well is 6.5 Bcf in four separate stringers. Three optimum brine-disposal sands and the best brine-disposal site were selected in Northeast Hitchcock field based on sand-body complexity, thickness, depth, and brine-disposal capacity. The equilibrium distribution of inorganic species in different combinations in the produced waters at surface and formation temperatures and pH was estimated from chemical analyses. SOLMNEQ computations suggest carbonate scaling may occur in surface equipment of Miocene disposal sandstones unless inhibitors are used. At Northeast Hitchcock field, well-winnowed sandstones of shallow-marine origin compose the major reservoir sands and act as preferential conduits for fluid migration. Dislodged, abundant authigenic kaolinite in these sands can plug pores during production, suggesting a maximum rate of production will need to be determined to avoid reservoir damage.Bureau of Economic Geolog

State of Texas Advanced Oil and Gas Resource Recovery

The objective of the State of Texas Advanced Resource Recovery program, Project STARR, is to increase royalty income to the Permanent School Fund through the drilling of profitable wells on State lands. The Bureau of Economic Geology (Bureau) receives $450,000 per year from the State to pay salaries of Bureau researchers involved in Project STARR who analyze State lands properties and databases and then advise operators how to increase production. The State requires the STARR program to be revenue-positive; that is, the Bureau has to cause an amount of new royalty revenue to flow into the Permanent School Fund that exceeds the$900,000 that is appropriated to the program every 2 years by the Legislature. This report summarizes the STARR studies that have been done since the inception of the program and documents that in the 2-year period since the last STARR report, the program is revenue-positive by a factor of 2.7. The term proved oil reserves refers to oil that will be produced using currently deployed technology. On State Lands, proved oil reserves total 270 million barrels (MMbbl), which is only 8 percent of the 3.43 billion barrels (Bbbl) of oil that is projected to remain across these properties at reservoir abandonment (Holtz and Garrett, 1997). Of this 3.43 Bbbl, 1.6 Bbbl is mobile oil that will not be recovered unless advanced geological, geophysical, and engineering technologies are applied to State Lands reservoirs. This potentially recoverable amount (1.6 Bbbl) nearly equals the cumulative production on State Lands.Bureau of Economic Geolog

Coalbed Methane Potential of the Greater Green River, Piceance, Powder River and Raton Basins

Coalbed methane potential of the Greater Green River, Piceance, Powder River, and Raton Basins was evaluated in the context of geologic and hydrologic characteristics identified in the San Juan Basin, the nation's leading coalbed methane producing basin. The major comparative criteria were (1) coalbed methane resources, (2) geologic and hydrologic factors that predict areas of high gas producibility and high coalbed reservoir permeability, and (3) coalbed thermal maturity. These technical criteria were expanded to include structure, depositional systems, and database and then combined with economic criteria (production, industry activity, and pipeline availability) to evaluate the coalbed methane potential of the basins. The Greater Green River and Piceance Basins have primary potential to make a significant near-term contribution to the nation's gas supply. These basins have large gas resources, high-rank coals, high gas contents, and established coalbed methane production. The Greater Green River Basin has numerous coalbed methane targets, good coal-seam permeability, and extensive hydrologic areas favorable for production. The Powder River and Raton Basins were judged to have secondary potential. Coal beds in the Powder River Basin are thermally immature and produce large volumes of water; the Raton Basin has a poor database and has no gas pipeline infrastructure. Low production and minimal industry activity further limit the near-term potential of the Raton Basin. However, if economic criteria are discounted and only major technical criteria are considered, the Greater Green River and Raton Basins are assigned primary potential. The Raton Basin's shallow, thermally mature coal beds of good permeability are attractive coalbed methane targets, but low coal-seam permeability limits the coalbed methane potential of the Piceance Basin.Bureau of Economic Geolog

Coordination of Geological and Engineering Research in Support of the Gulf Coast Co-Production Program - Final Report

At Northeast Hitchcock field, the presence of the Skolithos assemblage and other structures has supported the interpretation of shallow-marine, tidal, distributary-mouth-bar, and channel depositional environments for most of the major reservoir sandstones. Several shaly horizons exhibit characteristics of interdistributary bays, and the Frio A is capped by a thin sequence of crevasse splays and washover sands that represent the initiation of the transgression that overlapped the Frio in Anahuac times. The high-energy depositional environment of reworked distributary-mouth-bar sandstones is the major control of the high porosity (around 30 percent) and permeability (around 1,000 millidarcies) in Frio A sandstones at Northeast Hitchcock field. Well-winnowed sandstones with high porosities and permeabilities contain abundant authigenic kaolinite and have served as preferential conduits for migrating acid waters and major fluid flow during co-production. Authigenic clay can create fluid production problems due to its delicate structure. Dislodged clay may obstruct pore throats at high production rates, necessitating the determination of a maximum safe rate of fluid production for co-produced wells. Middle and lower Miocene barrier island sands, buried at depths from 3,500 to 6,800 feet in Northeast Hitchcock field, have the potential to receive large volumes of co-produced brines from the Frio 1-A reservoir. These sands exhibit high permeabilities exceeding 2,000 millidarcies, are internally homogeneous, and are laterally extensive in the field area. The 6,150-foot sand (lower Miocene) was chosen for initial brine disposal in the H.D.S. Thompson No. 3 brine-disposal well based on these criteria. The 3,780-foot sand (middle Miocene) is recommended for future up-hole brine disposal in the H.D.S. Thompson No. 3 well because it is shallower, requiring less injection pressure and lower costs for brine disposal.Bureau of Economic Geolog