Play Types

Tight Gas Sands

Coming Soon!
Recent Posts
No posts yet.
The estimated ultimate recovery (EUR) is one of the most significant properties of tight-gas sandstone reservoirs, but it remains difficult to predict. Estimated ultimate recovery is dependent on the success of stimulation by hydraulic fracturing, the existence and connectivity of natural fractures, and as illustrated in this article, the pore structure of the matrix.
Desktop /Portals/0/images/_site/AAPG-newlogo-vertical-morepadding.jpg?width=100&h=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true 8602

Carbon capture and sequestration (CCS) is perhaps commercially viable but not proven at commercial scale, according to 100 clean-energy experts that recently released their recommendations to the White House: "Powering Forward: Presidential and Executive Agency Actions to Drive Clean Energy in America."

Desktop /Portals/0/PackFlashItemImages/WebReady/carbon-capture-and-sequestration-expensive-and-unproven-2014-02feb-03.jpg?width=100&h=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true 12373

Every six months, chairs of the Energy Minerals Division committees convene and report on developments in the areas they cover. In this column, we highlight important observations from these recent reports.

Desktop /Portals/0/PackFlashItemImages/WebReady/report-a-state-of-the-emd-union-update-2014-02feb-hero.jpg?width=100&h=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true 3800

Using examples from shale reservoirs worldwide, I demonstrate the diversity of shale-hosted fracture systems and present evidence for how and why various fractures systems form. Core and outcrop observations, strength tests on shale and on fractures in core, and geomechanical models allow prediction of fracture patterns and attributes that can be taken into account in well placement and hydraulic fracture treatment design. Both open and sealed fractures can interact with and modify hydraulic fracture size and shape. Open fractures can enhance reservoir permeability but may conduct treatment fluids great distances, in some instances possibly aseismically.

Desktop /Portals/0/images/_site/AAPG-newlogo-vertical-morepadding.jpg?width=100&h=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true 3082

In prospective basins affected by exhumation, uncertainty commonly exists regarding the maximum burial depths of source, reservoir, and seal horizons. One such basin is the Otway Basin, an important gas province in southeastern Australia, which has witnessed several exhumation events. Here, we present estimates of net exhumation magnitudes for 110 onshore and offshore petroleum wells based on the sonic transit time analyses of Lower Cretaceous fluvial shales. Our results show significant post-Albian net exhumation in the eastern onshore Otway Basin (gt1500 m [sim4920 ft]) and a generally minor net exhumation (lt200 m [sim655 ft]) elsewhere in the Otway Basin, consistent with estimates based on thermal history data. The distribution of net exhumation magnitudes in relation to mid-Cretaceous and Neogene compressional structures indicates that exhumation was dominantly controlled by short-wavelength basin inversion driven by plate-boundary forces.

Deeper burial coupled with high geothermal gradients in the onshore eastern Otway Basin and along the northern basin margin during the early Cretaceous have rendered Lower Cretaceous source rocks mostly overmature, with any remaining hydrocarbons from the initial charge likely to be trapped in tightly compacted reservoirs and/or secondary (fracture-related) porosity. However, the embrittlement of these reservoirs during their deeper burial may present opportunities for the development of low-permeability plays through hydraulic fracturing where smectite clay minerals are illitized. Source rocks at near-maximum burial at present day are at temperatures suitable for gas generation, with key controls on prospectivity in these areas including the sealing potential of faulted traps and the relationship between charge and trap development.

Desktop /Portals/0/PackFlashItemImages/WebReady/quantifying-Cretaceous-Cenozoic-exhumation-in-the-Otway-Basin.jpg?width=100&h=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true 3252

Global demand for natural gas continues to grow and the search is on to meet that demand in both the eastern and western hemispheres.

Desktop /Portals/0/PackFlashItemImages/WebReady/Explorer-Cover-2013-07jul-thumb.jpg?width=100&h=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true 2537

Regional variations in thickness and facies of clastic sediments are controlled by geographic location within a foreland basin. Preservation of facies is dependent on the original accommodation space available during deposition and ultimately by tectonic modification of the foreland in its postthrusting stages. The preservation of facies within the foreland basin and during the modification stage affects the kinds of hydrocarbon reservoirs that are present.

This is the case for the Cretaceous Mowry Shale and Frontier Formation and equivalent strata in the Rocky Mountain region of Colorado, Utah, and Wyoming. Biostratigraphically constrained isopach maps of three intervals within these formations provide a control on eustatic variations in sea level, which allow depositional patterns across dip and along strike to be interpreted in terms of relationship to thrust progression and depositional topography.

The most highly subsiding parts of the Rocky Mountain foreland basin, near the fold and thrust belt to the west, typically contain a low number of coarse-grained sandstone channels but limited sandstone reservoirs. However, where subsidence is greater than sediment supply, the foredeep contains stacked deltaic sandstones, coal, and preserved transgressive marine shales in mainly conformable successions. The main exploration play in this area is currently coalbed gas, but the enhanced coal thickness combined with a Mowry marine shale source rock indicates that a low-permeability, basin-centered play may exist somewhere along strike in a deep part of the basin.

In the slower subsiding parts of the foreland basin, marginal marine and fluvial sandstones are amalgamated and compartmentalized by unconformities, providing conditions for the development of stratigraphic and combination traps, especially in areas of repeated reactivation. Areas of medium accommodation in the most distal parts of the foreland contain isolated marginal marine shoreface and deltaic sandstones that were deposited at or near sea level lowstand and were reworked landward by ravinement and longshore currents by storms creating stratigraphic or combination traps enclosed with marine shale seals.

Paleogeographic reconstructions are used to show exploration fairways of the different play types present in the Laramide-modified, Cretaceous foreland basin. Existing oil and gas fields from these plays show a relatively consistent volume of hydrocarbons, which results from the partitioning of facies within the different parts of the foreland basin.

Desktop /Portals/0/PackFlashItemImages/WebReady/controls-on-the-deposition-and-preservation.jpg?width=100&h=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true 3743

After World War II, the United States suddenly found itself with nuclear explosives, a tool for which there were few obvious uses other than spectacular and indiscriminate destruction. 

Desktop /Portals/0/PackFlashItemImages/WebReady/a-truly-massive-stimulation-technique-2013-03mar-hero.jpg?width=100&h=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true 2326
The American Association of Petroleum Geologists sponsored a Hedberg Research Conference on Enhanced Geothermal Systems in Napa, California, March 18 to 23, 2011. The workshop was attended by 67 participants from 10 different countries: United States, Australia, Austria, Canada, Colombia, Germany, Malaysia, Netherlands, New Zealand, and Norway.
Desktop /Portals/0/PackFlashItemImages/WebReady/Bulletin-hero-2013-03mar.jpg?width=100&h=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true 3678
Although conventional reservoirs dominate the Bohai Basin, China, a new type of sandstone reservoir also exists in the Dongpu depression that has a low matrix porosity (tight) in which natural fractures govern both permeability and porosity. These fractured sandstones are located on a structurally modified buried hill underlying Paleogene mudstones, and are truncated along an angular unconformity. The fractured sandstone oils of the Triassic Liujiagou, Heshanggou, and Ermaying Formations are derived from the Paleogene Shahejie Formation, which reached peak oil generation and expulsion during the Oligocene to early Miocene (32.8–15.6 Ma). Gas was generated primarily during the Paleogene from Carboniferous and Permian coals. Petrographic evidence suggests that oil and gas emplacement followed the compaction and cementation of the Triassic sandstone reservoirs. Fluid inclusion evidence and burial history analysis suggest that fractures developed before oil emplacement but may have coincided with peak gas generation, which suggests that oil and gas mainly migrated and accumulated in fractures.
Desktop /Portals/0/PackFlashItemImages/WebReady/fractured-tight-sandstone-oil.jpg?width=100&h=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true 3673
«« First |1 2 3 4 5 6 7 8 | Last ››
In-Person Training
Denver Colorado United States 30 May, 2015 31 May, 2015 14522 Desktop /Portals/0/PackFlashItemImages/WebReady/ace2015-ft-04-hero.jpg?width=100&height=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true Oil Sands, Oil Shale, Shale Gas, Tight Gas Sands, Sedimentology and Stratigraphy, Engineering, Reservoir Characterization, Field Trips, Conventions, Pre-Convention
Denver, Colorado, United States
30-31 May 2015

During this two-day field trip, we will examine classic exposures of the Middle to Upper Cretaceous (Cenomanian to Campanian) strata in the Southern Denver Basin near Pueblo, Colorado.

Golden Colorado United States 04 June, 2015 06 June, 2015 14707 Desktop /Portals/0/PackFlashItemImages/WebReady/ace2015-ft-12-hero.jpg?width=100&height=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true Coalbed Methane, Oil Shale, Oil Sands, Shale Gas, Tight Gas Sands, Engineering, Reservoir Characterization, Field Trips, Conventions, Post-Convention
Golden, Colorado, United States
4-6 June 2015
This three-day field trip will examine examples of tight-oil reservoirs (Cretaceous Niobrara Formation, Codell member of Carlile Formation from the Denver and North Park basins), tight-gas reservoirs (Cretaceous J Sandstone, Codell and Williams Fork Sandstone, from both the Denver and Piceance basins), CBM reservoirs (Cretaceous Cameo Coals from the Piceance Basin) and potential oil shale resources (Green River Formation of the Piceance Basin).
San Antonio Texas United States 18 July, 2015 18 July, 2015 14514 Desktop /Portals/0/PackFlashItemImages/WebReady/sc-Geomechanics-For-Completion-Optimization-In-Unconventionals-hero.jpg?width=100&height=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true Structure, Geomechanics and Fracture Analysis, Oil Sands, Oil Shale, Shale Gas, Tight Gas Sands, Coalbed Methane, Production, Engineering, Hydraulic Fracturing, Development and Operations
San Antonio, Texas, United States
18 July 2015

Geomechanics – in both completions and drilling operations – has become a critical technology in the development of Unconventional Plays. This course presents the basics of oil field geomechanics and its application to unconventional developments; specifically, the role of stress, pore pressure, mechanical properties, and natural fractures on hydraulic fracturing operations.

San Antonio Texas United States 18 July, 2015 19 July, 2015 13769 Desktop /Portals/0/PackFlashItemImages/WebReady/hero-assessment-forecasting-and-decision-making-in-unconventional-resource-plays.jpg?width=100&height=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true Business and Economics, Oil Sands, Oil Shale, Shale Gas, Tight Gas Sands, Coalbed Methane, Risk Analysis
San Antonio, Texas, United States
18-19 July 2015
This course is oriented towards the recognition and characterization of uncertainty in unconventional reservoirs. Starting with resource/reservoir assessment methods, it moves through the full unconventional value-chain. This two-day exercise and example filled workshop provides participants with the techniques and reasoning needed to validly assess the merits of the search for, and development of, unconventional resource plays.
Abu Dhabi United Arab Emirates 04 October, 2015 06 October, 2015 13097 Desktop /Portals/0/PackFlashItemImages/WebReady/third-eage-aapg-workshop-hero.jpg?width=100&height=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true Tight Gas Sands, Petrophysics and Well Logs, Geophysics, Engineering, Business and Economics, Economics, Resource Estimates, Development and Operations, Reservoir Characterization
Abu Dhabi, United Arab Emirates
4-6 October 2015

This workshop is the outgrowth of continued cooperation between AAPG & EAGE to develop a series of multi-disciplined gatherings dedicated to understanding, completing & producing tight sandstone & carbonate reservoirs.

San Antonio Texas United States 01 December, 2015 02 December, 2015 21310 Desktop /Portals/0/PackFlashItemImages/WebReady/gtw-revitalizing-reservoicrs-texas-gulf-coast-latin-12dec-2015-hero.jpg?width=100&height=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true Business and Economics, Engineering, Development and Operations, Production, Drive Mechanisms, Depletion Drive, Water Drive, Hydraulic Fracturing, Primary Recovery, Secondary Recovery, Tertiary Recovery, Chemical Flooding Processes, Reservoir Characterization, Geochemistry and Basin Modeling, Oil Seeps, Oil and Gas Analysis, Petroleum Systems, Geophysics, Seismic, Petrophysics and Well Logs, Structural Traps, Subsalt Traps, Tight Gas Sands, Shale Gas, Fractured Carbonate Reservoirs, Stratigraphic Traps
San Antonio, Texas, United States
1-2 December 2015
This workshop brings together new technologies, practices, and procedures that can be applied to new and mature fields in order to revitalize them and increase / optimize recovery. The presentations will focus on case studies, research findings, and field applications for new and existing plays, including Texas, Gulf Coast region, and Latin America.
Online Training
12 July, 2012 12 July, 2012 1490 Desktop /Portals/0/PackFlashItemImages/WebReady/oc-es-shale-wells-making-the-engineering-fit-what-geology-offers.jpg?width=100&height=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true
12 July 2012

This presentation will look at well placement vertically in the pay, well azimuth and well trajectory with explanations of how geology and post-depositional effects can make the difference between a successful well and a failure.

28 April, 2011 28 April, 2011 1471 Desktop /Portals/0/PackFlashItemImages/WebReady/oc-es-niobrara-petroleum-system-a-major-tight-resource-play.jpg?width=100&height=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true
28 April 2011

The Niobrara Petroleum System of the U.S. Rocky Mountain Region is a major tight petroleum resource play.

21 May, 2009 21 May, 2009 1443 Desktop /Portals/0/PackFlashItemImages/WebReady/oc-es-how-tight-is-your-gas.jpg?width=100&height=100&mode=crop&anchor=middlecenter&quality=75amp;encoder=freeimage&progressive=true
21 May 2009

This e-symposium introduces you to the practical benefits of thermal profiling for a variety of unconventional oil and gas projects, including tight gas sands, oil shale, low-gravity oil.

Coming Soon

Check back often. "Find an Expert" feature is coming online soon!