Modeling and simulation of unconventional reservoirs are much more complicated than the conventional reservoir modeling, because of their complex flow characteristics. Mechanisms, which control the flow in the reservo...Modeling and simulation of unconventional reservoirs are much more complicated than the conventional reservoir modeling, because of their complex flow characteristics. Mechanisms, which control the flow in the reservoir, are still under the investigation of researchers. However, it is important to investigate applications of mechanisms which are present to our knowledge. This paper presents the theory and applications of flow mechanisms in unconventional reservoir modeling. It is a well-known fact that most of the reservoir flow problems are non-linear due to pressure dependency of particular parameters. It is also widely accepted that fully numerical solutions are costly both computational and time wise. Therefore, the presented model in this paper follows semi-analytical solution methods. Gas adsorption in unconventional reservoirs is the major pressure dependent mechanism;in addition existence of natural fractures is also taken considerable attention. This paper aims to investigate combined effect of existence of natural fractures gas adsorption, and gas slippage effect while keeping the computational effort in acceptable range. Unlike the existing literature (Langmuir is widely used), BET multi-layer isotherm employed in this paper for gas adsorption modeling. A modified dual porosity modeling is used for natural fracture and gas slippage effect modeling. For model verification purposes a history matched is performed with real field data from Marcellus shale. The proposed model in this paper shows a good agreement with the field data. It is observed that BET isotherm models early time production performance more accurately than Langmuir isotherm. It is also concluded that gas adsorption significantly improves the production performances of unconventional reservoirs, with natural fractures. In addition, gas slippage has a slight effect in long term production.展开更多
INTRODUCTION Hydraulic fracturing occurs when high pressure fluids primarily consisting of water and sand are pumped at high pressure into subsurface formations,typically shale that contains natural gas and/or oil.The...INTRODUCTION Hydraulic fracturing occurs when high pressure fluids primarily consisting of water and sand are pumped at high pressure into subsurface formations,typically shale that contains natural gas and/or oil.The high pressure fluid causes the rock to fracture.The new fractures increase the surface area of the shale and better interconnect previously existing fractures,allowing more natural gas and/or oil to be pumped from the formation.Modern hydraulic fracturing,referred to as“fracking,”is an evolving technology that largely began after 2000 and has significantly increased natural gas production in the United States in the past five years with corresponding decreases in natural gas prices.展开更多
A passive rainwater harvesting technique was used to design a sustainable landscape for a residential lot located in the desert. The design was adapted to the Desert Southwest region of the United States based on thir...A passive rainwater harvesting technique was used to design a sustainable landscape for a residential lot located in the desert. The design was adapted to the Desert Southwest region of the United States based on thirty years of daily historical climate data including precipitation and reference evapotranspiration (ET0). Four cities including El Paso, TX, Albuquerque, NM, Phoenix, AZ, and Pahrump, NV, were selected to represent the area. The residential lot was broken up into micro-watersheds reflecting the runoff of water from each separate portion of the house roof, driveway, and lawn area. The paper explains in detail the design steps for one of the micro-watersheds where water retention and infiltration structures were distributed throughout the soil area to capture stormwater runoff close to its source. A passive rainwater capture landscape was obtained by using the stormwater captured in the infiltration structures and stored in the surrounding soil. Native vegetation (shrubs and trees) will use this water exclusively for growth. These plants will not require watering once their root establishment period has passed, except in extreme droughts. Meanwhile, stormwater discharge from the lot will decrease and the groundwater recharge will increase. Results indicate that the current urban water budget can be made sustainable by replacing watering of landscape by municipal water with harvested stormwater. This results in a relatively lush and shady environment even in desert climates. The success is an artifact of the tendency of urban watersheds to increase the volume of stormwater relative to pre-development conditions.展开更多
文摘Modeling and simulation of unconventional reservoirs are much more complicated than the conventional reservoir modeling, because of their complex flow characteristics. Mechanisms, which control the flow in the reservoir, are still under the investigation of researchers. However, it is important to investigate applications of mechanisms which are present to our knowledge. This paper presents the theory and applications of flow mechanisms in unconventional reservoir modeling. It is a well-known fact that most of the reservoir flow problems are non-linear due to pressure dependency of particular parameters. It is also widely accepted that fully numerical solutions are costly both computational and time wise. Therefore, the presented model in this paper follows semi-analytical solution methods. Gas adsorption in unconventional reservoirs is the major pressure dependent mechanism;in addition existence of natural fractures is also taken considerable attention. This paper aims to investigate combined effect of existence of natural fractures gas adsorption, and gas slippage effect while keeping the computational effort in acceptable range. Unlike the existing literature (Langmuir is widely used), BET multi-layer isotherm employed in this paper for gas adsorption modeling. A modified dual porosity modeling is used for natural fracture and gas slippage effect modeling. For model verification purposes a history matched is performed with real field data from Marcellus shale. The proposed model in this paper shows a good agreement with the field data. It is observed that BET isotherm models early time production performance more accurately than Langmuir isotherm. It is also concluded that gas adsorption significantly improves the production performances of unconventional reservoirs, with natural fractures. In addition, gas slippage has a slight effect in long term production.
文摘INTRODUCTION Hydraulic fracturing occurs when high pressure fluids primarily consisting of water and sand are pumped at high pressure into subsurface formations,typically shale that contains natural gas and/or oil.The high pressure fluid causes the rock to fracture.The new fractures increase the surface area of the shale and better interconnect previously existing fractures,allowing more natural gas and/or oil to be pumped from the formation.Modern hydraulic fracturing,referred to as“fracking,”is an evolving technology that largely began after 2000 and has significantly increased natural gas production in the United States in the past five years with corresponding decreases in natural gas prices.
文摘A passive rainwater harvesting technique was used to design a sustainable landscape for a residential lot located in the desert. The design was adapted to the Desert Southwest region of the United States based on thirty years of daily historical climate data including precipitation and reference evapotranspiration (ET0). Four cities including El Paso, TX, Albuquerque, NM, Phoenix, AZ, and Pahrump, NV, were selected to represent the area. The residential lot was broken up into micro-watersheds reflecting the runoff of water from each separate portion of the house roof, driveway, and lawn area. The paper explains in detail the design steps for one of the micro-watersheds where water retention and infiltration structures were distributed throughout the soil area to capture stormwater runoff close to its source. A passive rainwater capture landscape was obtained by using the stormwater captured in the infiltration structures and stored in the surrounding soil. Native vegetation (shrubs and trees) will use this water exclusively for growth. These plants will not require watering once their root establishment period has passed, except in extreme droughts. Meanwhile, stormwater discharge from the lot will decrease and the groundwater recharge will increase. Results indicate that the current urban water budget can be made sustainable by replacing watering of landscape by municipal water with harvested stormwater. This results in a relatively lush and shady environment even in desert climates. The success is an artifact of the tendency of urban watersheds to increase the volume of stormwater relative to pre-development conditions.
