Long-Period Slow Wave in Hydrocarbon-Water-Gas Reservoirs

2007 ◽  
Author(s):  
P. Krauklis ◽  
A. Krauklis
Keyword(s):  
Slow Wave ◽  
Gas Reservoirs ◽  
Long Period ◽  
Water Gas

scholarly journals Water-Gas Two-Phase Flow Behavior of Multi-Fractured Horizontal Wells in Shale Gas Reservoirs

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 664 ◽  
Author(s):  
Lei Li ◽  
Guanglong Sheng ◽  
Yuliang Su
Keyword(s):  
Organic Matter ◽  
Shale Gas ◽  
Flow Behavior ◽  
Horizontal Wells ◽  
Gas Production ◽  
Phase Flow ◽  
Gas Reservoirs ◽  
Two Phase ◽  
Fractured Horizontal Wells ◽  
Water Gas

Hydraulic fracturing is a necessary method to develop shale gas reservoirs effectively and economically. However, the flow behavior in multi-porosity fractured reservoirs is difficult to characterize by conventional methods. In this paper, combined with apparent porosity/permeability model of organic matter, inorganic matter and induced fractures, considering the water film in unstimulated reservoir volume (USRV) region water and bulk water in effectively stimulated reservoir volume (ESRV) region, a multi-media water-gas two-phase flow model was established. The finite difference is used to solve the model and the water-gas two-phase flow behavior of multi-fractured horizontal wells is obtained. Mass transfer between different-scale media, the effects of pore pressure on reservoirs and fluid properties at different production stages were considered in this model. The influence of the dynamic reservoir physical parameters on flow behavior and gas production in multi-fractured horizontal wells is studied. The results show that the properties of the total organic content (TOC) and the inherent porosity of the organic matter affect gas production after 40 days. With the gradual increase of production time, the gas production rate decreases rapidly compared with the water production rate, and the gas saturation in the inorganic matter of the ESRV region gradually decreases. The ignorance of stress sensitivity would cause the gas production increase, and the ignorance of organic matter shrinkage decrease the gas production gradually. The water film mainly affects gas production after 100 days, while the bulk water has a greater impact on gas production throughout the whole period. The research provides a new method to accurately describe the two-phase fluid flow behavior in different scale media of fractured shale gas reservoirs.

Zmiany parametrów mieszaniny gazu ziemnego z wodorem w trakcie eksploatacji komory magazynowej w kawernie solnej

Nafta-Gaz ◽  
2020 ◽  
Vol 76 (11) ◽  
pp. 799-806
Author(s):  
Paweł Budak ◽  
◽  
Tadeusz Szpunar ◽  
Keyword(s):  
Hydrogen Content ◽  
Distribution Network ◽  
Calorific Value ◽  
Gas Reservoirs ◽  
Heating Value ◽  
Salt Domes ◽  
Depleted Gas Reservoirs ◽  
Salt Caverns ◽  
Short Time ◽  
Water Gas

Underground gas stores are built in depleted gas reservoirs or in salt domes or salt caverns. In the case of salt caverns, the store space for gas is created by leaching the salt using water. Gas stores in salt caverns are capable to provide the distribution network with large volumes of gas in a short time and cover the peak demand for gas. The salt caverns are also capable to store large volumes of gas in case when there is too much gas on a market. Generally, the salt caverns are used to mitigate the fluctuation of gas demand, specifically during winter. The gas provided to the distribution network must satisfy the requirements regarding its heating value, calorific value, volumetric content of hydrogen and the Wobbe number. Large hydrogen content reduces the calorific value as well as the heating value of gas and thus its content must be regulated to keep these values at the acceptable level. One should also remember that every portion of gas which was used to create the gas/hydrogen mixture may have different parameters (heating value and calorific value) because it may come from different sources. The conclusion is that the hydrogen content and the heating value must be known at every moment of gas store exploitation. The paper presents an algorithm and a computer program which may be used to calculate the hydrogen content (volumetric percentage), heating value and calorific value (plus the Wobbe number) of gas collected from the salt cavern at every moment of cavern exploitation. The possibility of the presence of non-flammable components in the mixture and their effect on the heat of combustion / calorific value were considered. An exemplary calculation is provided.

Long-period long-duration seismic events during hydraulic stimulation of shale and tight-gas reservoirs — Part 2: Location and mechanisms

Geophysics ◽  
2013 ◽  
Vol 78 (6) ◽  
pp. KS109-KS117 ◽  
Author(s):  
Indrajit Das ◽  
Mark D. Zoback
Keyword(s):  
Fluid Pressure ◽  
Seismic Events ◽  
Tight Gas ◽  
Gas Reservoirs ◽  
Data Set ◽  
Hydraulic Stimulation ◽  
Tight Gas Reservoirs ◽  
Long Period ◽  
Long Duration ◽  
Stimulation Of

Long-period long-duration (LPLD) seismic events that have been observed during hydraulic stimulation of shale-gas and tight-gas reservoirs appear to represent slow shear slip on relatively large faults. Within the limitations of the recording geometry, we determine the areas in the reservoirs where the events are located in two case studies in the Barnett shale. In one data set, LPLD events appear to occur in the region where the density of natural fractures as well as the fluid pressure during pumping were highest. In the other data set, the LPLD events are observed to occur between two wells and seem to establish a hydraulic connection between them. In both data sets, the LPLD events occur in areas with very few located microearthquakes. A combination of factors such as high fluid pressure and/or high clay content is potentially responsible for the slowly slipping faults. The LPLD events appear to be occurring only on faults large enough to produce a sequence of slow slip events. We suggest that these slowly slipping faults contribute appreciably to the stimulation of these extremely low-permeability reservoirs and hence mapping the distribution of faults and fractures and areas with rock properties that favor slow, sustained slip, can help in optimizing production.

Analysis Development Status of A12 Reservoir

2013 ◽  
Vol 650 ◽  
pp. 664-666
Author(s):  
Lei Zhang ◽  
Guo Ming Liu
Keyword(s):  
Water Distribution ◽  
Bottom Water ◽  
Oil And Gas ◽  
Water Reservoir ◽  
Gas Reservoirs ◽  
Gas Drive ◽  
Oil And Gas Reservoir ◽  
Water Gas ◽  
Oil Gas ◽  
Gas Bearing

A12 oil and gas reservoirs in L Oilfield Carboniferous carbonate rocks of oil and gas bearing system, saturated with the gas cap and edge water and bottom water reservoir. The A12 oil and gas reservoir structure the relief of the dome-shaped anticline, oil, gas and water distribution controlled by structure, the gas interface -2785 meters above sea level, the oil-water interface altitude range -2940 ~-2980m, average-2960m. Average reservoir thickness of 23m, with a certain amount of dissolved gas drive and gas cap gas drive energy, but not very active edge and bottom water, gas cap drive index.

scholarly journals A 160,000-year-old history of tectonically controlled methane seepage in the Arctic

2019 ◽  
Vol 5 (8) ◽  
pp. eaaw1450 ◽  
Author(s):  
Tobias Himmler ◽  
Diana Sahy ◽  
Tõnu Martma ◽  
Gerhard Bohrmann ◽  
Andreia Plaza-Faverola ◽  
...  
Keyword(s):  
Deep Water ◽  
Glacial Maximum ◽  
The Arctic ◽  
Gas Reservoirs ◽  
Methane Release ◽  
Last Glacial ◽  
Methane Seepage ◽  
History Of ◽  
Water Gas ◽  
The Last Glacial

The geological factors controlling gas release from Arctic deep-water gas reservoirs through seabed methane seeps are poorly constrained. This is partly due to limited data on the precise chronology of past methane emission episodes. Here, we use uranium-thorium dating of seep carbonates sampled from the seabed and from cores drilled at the Vestnesa Ridge, off West Svalbard (79°N, ~1200 m water depth). The carbonate ages reveal three emission episodes during the Penultimate Glacial Maximum (~160,000 to 133,000 years ago), during an interstadial in the last glacial (~50,000 to 40,000 years ago), and in the aftermath of the Last Glacial Maximum (~20,000 to 5,000 years ago), respectively. This chronology suggests that glacial tectonics induced by ice sheet fluctuations on Svalbard mainly controlled methane release from Vestnesa Ridge. Data corroborate past methane release in response to Northern Hemisphere cryosphere variations and suggest that Arctic deep-water gas reservoirs are sensitive to temperature variations over Quaternary time scales.

Concept to Design: A Novel Seawater Intake Riser System

2014 ◽  
Author(s):  
Venkat Chakkarapani ◽  
Gautam Chaudhury
Keyword(s):  
Large Diameter ◽  
Cost Effective ◽  
Process Technology ◽  
Gas Reservoirs ◽  
Glass Fiber Reinforced Plastic ◽  
Glass Fiber Reinforced ◽  
Reinforced Plastic ◽  
Low Stiffness ◽  
Cost Efficient ◽  
Water Gas

FLNG cooling process uses large volume of cold seawater drawn from 500–1000 feet below the mean sea level utilizing several vertical risers (20in–30in ID) hanging from the vessel. These risers have requirements very different from conventional risers supported at hang-off and seabed. The design challenges are hang-off loads (in both strength and fatigue), minimum bend radius (MBR) and interference. Hang-off loads can be lowered using low stiffness and light weight risers, but the associated deflections and riser motions will be excessive leading to low MBR and potential interference issues. On the other hand, interference and MBR issues can be addressed by using suffer and heavier weight risers, but this will increase hang-off loads and stresses at the platform base. Weight mass not only affects the dynamics but also provides valuable restoring moment thus helps to reduce static displacement due to current forces. Stiffness affects the bending deflections and helps achieve an acceptable MBR. Based on this, a novel alternative design for seawater intake is to use a single large diameter (60in-70in) steel caisson riser. This paper will briefly outline the preliminary concept verification and concentrate on the engineering of the concept in terms of design optimization, cost/schedule, construction, and installation. Other materials such as High Density Polyethylene Pipe (HDPE), Glass Fiber Reinforced Plastic (GFRP), will be examined for feasibility. FLNG process technology is continuing to develop to be safe, compact, and cost-efficient which also increases the possibilities of developing a number of stranded deep water gas reservoirs around the world. FLNG processes will become more efficient and cost effective with the proposed novel seawater intake system. Cost effectiveness will be evaluated in a qualitative manner.

Long-period, long-duration seismic events during hydraulic stimulation of shale and tight-gas reservoirs — Part 1: Waveform characteristics

Geophysics ◽  
2013 ◽  
Vol 78 (6) ◽  
pp. KS97-KS108 ◽  
Author(s):  
Indrajit Das ◽  
Mark D. Zoback
Keyword(s):  
Hydraulic Fracturing ◽  
Seismic Events ◽  
Tight Gas ◽  
Gas Reservoirs ◽  
Hydraulic Stimulation ◽  
Tight Gas Reservoirs ◽  
Long Period ◽  
Long Duration ◽  
Low Amplitude ◽  
Stimulation Of

Long-period long-duration (LPLD) seismic events are relatively low-amplitude signals that have been observed during hydraulic fracturing in several shale-gas and tight-gas reservoirs. These events are similar in appearance to tectonic tremor sequences observed in subduction zones and transform fault boundaries. LPLD events are predominantly composed of S-waves, but weaker P-waves have also been identified. In some cases, microearthquakes are observed during the events. Based on the similarity with tectonic tremors and our observations of several impulsive S-wave arrivals within the LPLD events, we interpret the LPLD events as resulting from the superposition of slow shear-slip events on relatively large faults. Most large LPLD waveforms appear to start as a relatively slower, low-amplitude precursor, lacking clear impulsive arrivals. We estimate the energy carried by the larger LPLD events to be [Formula: see text] times greater than a [Formula: see text] microseismic event that is typical of the events that occur during hydraulic stimulation. Over the course of the entire stimulation activity of five wells in the Barnett formation (each hydraulically fractured ten times), the LPLD events were found to cumulatively release over an order of magnitude higher energy than microearthquakes. The large size of these LPLD events, compared to microearthquakes, suggests that they represent slip on relatively large faults during stimulation of these extremely low-permeability reservoirs. Moreover, they imply that the accompanying slow slip on faults, probably mostly undetected, is a significant deformation process during multistage hydraulic fracturing.

scholarly journals Stimulation experiment of horizontal wells filled with permeable and water-blocking gravel in deepsea bottom-water gas reservoirs

2020 ◽  
Vol 7 (4) ◽  
pp. 390-396
Author(s):  
Yikun Liu ◽  
Haidong Wang ◽  
Wenbo Meng ◽  
Chong Zhang ◽  
Jiqiang Zhi ◽  
...  
Keyword(s):  
Bottom Water ◽  
Horizontal Wells ◽  
Gas Reservoirs ◽  
Water Blocking ◽  
Water Gas
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