The Experts below are selected from a list of 117 Experts worldwide ranked by ideXlab platform

Nicholas H. Gardiner - One of the best experts on this subject based on the ideXlab platform.

  • Laboratory Modeling of Mudcake Application and Erosion for Gravel-Pack Design in Horizontal Wells
    SPE Drilling & Completion, 2000
    Co-Authors: Thomas E. Becker, Nicholas H. Gardiner
    Abstract:

    Summary Successful gravel packing of long horizontal sections depends in part on preventing carrier fluid from leaking off to the surrounding permeable reservoir. This requires correctly designed drill-in fluids to apply a thin filter cake, rendering impermeable the sand formation at the wellbore wall. Filter cake must be embedded sufficiently within the formation interstitial space to resist scouring by flowing sand during the gravel-packing operation. This paper summarizes testing using a large-scale laboratory apparatus and procedure designed to test the effectiveness of drill-in fluids planned for use in horizontal wells recently drilled in the Gulf of Mexico. This paper shows the benefits of modeling a horizontal gravel-pack interval before attempting to install the gravel pack. Gravel-packing techniques for long horizontal well sections were evaluated with a laboratory model of a casing/Borehole Annulus. In the horizontal section modeled, permeability is sufficient to interfere with the transportation and distribution of pack sand from total depth to dogleg when positive differential pressure is maintained. The goal of this modeling experiment was to predict whether the formation's permeability at the sandface could be reduced enough to allow successful gravel packing without damaging the formation far beyond the sandface. Gravel-packing technology is well established for near-vertical wells, with off-the-shelf equipment and textbook procedures readily available. The exceptionally long producing intervals in horizontal wells present a greater challenge for gravel packing, however, interval permeability is, by design, continuous. This continuous permeability both enhances well productivity and allows increased wellbore fluid flow into reservoir rock. When the permeable formation absorbs the fluid energy necessary to evenly disperse pack sand throughout the section, sand bridging can result, restricting the flow before the pack sand is fully distributed across the entire interval. The laboratory model simulates the axial flow of drilling and/or completion fluids through an Annulus. The model has an impermeable confining wall (simulating the casing) and a permeable wall (simulating reservoir rock). Recently, it was used for testing the capacity of a drill-in fluid to reduce reservoir near-face permeability, and allow sand propagation throughout a long horizontal interval. Results obtained both in the laboratory and in subsequent field trials validate the use of a drill-in fluid in reducing near-sandface permeability. The procedure has been used successfully on multiple horizontal wells with typical horizontal section lengths of 1,000 to 2,500 ft. Plans are underway to continue the practice in additional wells. Introduction By increasing communication between the well and the payzone, horizontal drilling can increase oilwell production while minimizing operators' per-volume cost. A key decision in constructing a horizontal well is whether to case off the producing zone. If the section is to be cased, three options are available: conventional casing, which must be perforated; a slotted liner; and an uncemented, segmented liner.1 When feasible, an uncased production interval (true openhole completion) is preferred, since steel casing restricts hydrocarbon flow from the reservoir to the well. Operators must consider the obstacles and constraints associated with true openhole completions before making this decision. Such obstacles often include wellbore instability, sand production, and limitations on completion options and future well stimulation. This paper focuses on unconsolidated formations, particularly in sand intervals where the horizontal section must be gravel packed; and demonstrates how a laboratory test apparatus allowed users to predict the success of a gravel-packing strategy for horizontal wells. The gravel-packing process itself is risky.2 For example, the fluid transporting the gravel-packing sand must deliver the sand throughout the intended location; in this case, the entire horizontal interval (Fig. 1). The flow rate selection is constrained by differential pressure integrity (maximum allowable equivalent circulating density), yet it must be high enough to prevent excessive sand settling in the Annulus. For a successful gravel pack, the formation's permeability must be temporarily plugged off so that the transporting fluid remains in the wellbore and does not invade the formation. Forming this plug requires a properly designed drill-in fluid that can quickly create a filter cake that is both impermeable (to plug the formation) and degradable (to restore sandface permeability after the operation). A drill-in fluid's capacity to plug the sandface can be tested in a laboratory. If the drill-in fluid performs as intended, a conventional acid wash or other chemical treatment can remove all remnants of filter cake following the operation. If conditions permit, filter-cake materials in the sandface pores can be forced back through the gravel pack at the onset of production. Experimental Approach A major Gulf of Mexico operator developed plans for a series of horizontal wells for a large field, with horizontal-section lengths exceeding 2,000 ft. The lack of consolidation of the producing sands prohibited true openhole completions without some form of wellbore stability control. To maximize the flow of produced fluid, the operator chose to gravel pack the entire horizontal section instead of casing it. A properly formulated drill-in fluid3 was needed to produce a filter cake that could both plug the highly permeable (300 to 1000 md) sandface, and degrade to restore permeability to the formation after the gravel-packing sand was placed.

  • Laboratory Modeling of Gravel-Packing Process in Horizontal Producing Intervals
    All Days, 1999
    Co-Authors: Thomas E. Becker, Nicholas H. Gardiner
    Abstract:

    Abstract This paper shows the benefits of modeling a horizontal gravelpack interval before attempting to install the gravel pack. Gravelpacking techniques for long horizontal well sections were evaluated with a laboratory model of a casing/Borehole Annulus. In the horizontal section modeled, permeability is sufficient to interfere with the transportation and distribution of pack sand from total depth to dogleg when positive differential pressure is maintained. The goal of this modeling experiment was to predict whether the formation's permeability at the sandface could be reduced enough to allow successful gravel packing without damaging the formation far beyond the sandface. Gravel-packing technology is well established for near-vertical wells, with off-the-shelf equipment and textbook procedures readily available. The exceptionally long producing intervals in horizontal wells present a greater challenge for gravel packing, however. Interval permeability is, by design, continuous. This continuous permeability both enhances well productivity and allows increased wellbore fluid flow into reservoir rock. When the permeable formation absorbs the fluid energy necessary to evenly disperse pack sand throughout the section, sand bridging can result, restricting the flow before the pack sand is fully distributed across the entire interval. The laboratory model simulates the axial flow of drilling and/or completion fluids through an Annulus. The model has an impermeable confining wall (simulating the casing) and a permeable wall (simulating reservoir rock). Recently, it was used for testing the capacity of a drill-in fluid to reduce reservoir nearface permeability, and allow sand propagation throughout a long horizontal interval. Results obtained both in the laboratory and in subsequent field trials validate the use of a drill-in fluid in reducing near-sandface permeability. The procedure has been used successfully on multiple horizontal wells with typical horizontal section lengths of 1,000 to 2,500 ft. Plans are underway to continue the practice in additional wells.

Bradley Forbes - One of the best experts on this subject based on the ideXlab platform.

  • Utilizing a novel fiber optic technology to capture the axial responses of fully grouted rock bolts
    Journal of Rock Mechanics and Geotechnical Engineering, 2018
    Co-Authors: Nicholas Vlachopoulos, Daniel Cruz, Bradley Forbes
    Abstract:

    Abstract Rock bolts are one of the primary support systems utilized in underground excavations within the civil and mining engineering industries. Rock bolts support the weakened rock mass adjacent to the opening of an excavation by fastening to the more stable, undisturbed formations further from the excavation. The overall response of such a support element has been determined under varying loading conditions in the laboratory and in situ experiments in the past four decades; however, due to the limitations with conventional monitoring methods of capturing strain, there still exists a gap in knowledge associated with an understanding of the geomechanical responses of rock bolts at the microscale. In this paper, we try to address this current gap in scientific knowledge by utilizing a newly developed distributed optical strain sensing (DOS) technology that provides an exceptional spatial resolution of 0.65 mm to capture the strain along the rock bolt. This DOS technology utilizes Rayleigh optical frequency domain reflectometry (ROFDR) which provides unprecedented insight into various mechanisms associated with axially loaded rebar specimens of different embedment lengths, grouting materials, Borehole Annulus conditions, and Borehole diameters. The embedment length of the specimens was found to be the factor that significantly affected the loading of the rebar. The critical embedment length for the fully grouted rock bolts (FGRBs) was systematically determined to be 430 mm. The results herein highlight the effects of the variation of these individual parameters on the geomechanical responses FGRBs.

  • Utilizing a novel fiber optic technology to capture the axial responses of fully grouted rock bolts
    Elsevier, 2018
    Co-Authors: Nicholas Vlachopoulos, Daniel Cruz, Bradley Forbes
    Abstract:

    Rock bolts are one of the primary support systems utilized in underground excavations within the civil and mining engineering industries. Rock bolts support the weakened rock mass adjacent to the opening of an excavation by fastening to the more stable, undisturbed formations further from the excavation. The overall response of such a support element has been determined under varying loading conditions in the laboratory and in situ experiments in the past four decades; however, due to the limitations with conventional monitoring methods of capturing strain, there still exists a gap in knowledge associated with an understanding of the geomechanical responses of rock bolts at the microscale. In this paper, we try to address this current gap in scientific knowledge by utilizing a newly developed distributed optical strain sensing (DOS) technology that provides an exceptional spatial resolution of 0.65 mm to capture the strain along the rock bolt. This DOS technology utilizes Rayleigh optical frequency domain reflectometry (ROFDR) which provides unprecedented insight into various mechanisms associated with axially loaded rebar specimens of different embedment lengths, grouting materials, Borehole Annulus conditions, and Borehole diameters. The embedment length of the specimens was found to be the factor that significantly affected the loading of the rebar. The critical embedment length for the fully grouted rock bolts (FGRBs) was systematically determined to be 430 mm. The results herein highlight the effects of the variation of these individual parameters on the geomechanical responses FGRBs. Keywords: Fiber optic technology, Fully grouted rock bolts, Load transfer, Stress distributio

Xinguang Wang - One of the best experts on this subject based on the ideXlab platform.

  • a novel Borehole Annulus holdup calculation method based on pulsed neutron logging
    Applied Radiation and Isotopes, 2021
    Co-Authors: Xinguang Wang, Feng Zhang, Liangwen Zhou
    Abstract:

    Abstract Pulsed neutron logging tool (PNL), particularly small-diameter multifunction PNL, is an essential instrument used in casing well for evaluating residual oil saturation. In a Borehole with a multiple casing string structure, PNL tools log in the oil tube and even the space between the casing and oil tube. Borehole/Annulus holdup have a significant influence on the evaluation of oil saturation. Hence, the requirement of the estimation of Borehole/Annulus liquid holdup is highlighted. This study proposes a new method to determine the Annulus oil holdup in a casing well with a complex string structure. For this method, the Annulus holdup are derived from ΔS, which is defined as the difference between the relative variations of carbon/oxygen and carbon/hydrogen ratios. To demonstrate the feasibility of the proposed method, we first simulate the responses of ΔS under various Borehole and formation conditions using the Monte Carlo method. The outcome shows that ΔS covaries with Annulus oil holdup, confirming the feasibility of the proposed method in theory. The proposed method is applied to real data measured in an offshore production well. The result confirms that the formation water saturation calculated by the proposed method agrees well with the actual well production status, further confirming that the proposed method has a promising application in residual oil dynamic monitoring.

  • A novel Borehole/Annulus holdup calculation method based on pulsed neutron logging.
    Applied radiation and isotopes : including data instrumentation and methods for use in agriculture industry and medicine, 2020
    Co-Authors: Xinguang Wang, Feng Zhang, Ma Huanying, Zhou Liangwen
    Abstract:

    Abstract Pulsed neutron logging tool (PNL), particularly small-diameter multifunction PNL, is an essential instrument used in casing well for evaluating residual oil saturation. In a Borehole with a multiple casing string structure, PNL tools log in the oil tube and even the space between the casing and oil tube. Borehole/Annulus holdup have a significant influence on the evaluation of oil saturation. Hence, the requirement of the estimation of Borehole/Annulus liquid holdup is highlighted. This study proposes a new method to determine the Annulus oil holdup in a casing well with a complex string structure. For this method, the Annulus holdup are derived from ΔS, which is defined as the difference between the relative variations of carbon/oxygen and carbon/hydrogen ratios. To demonstrate the feasibility of the proposed method, we first simulate the responses of ΔS under various Borehole and formation conditions using the Monte Carlo method. The outcome shows that ΔS covaries with Annulus oil holdup, confirming the feasibility of the proposed method in theory. The proposed method is applied to real data measured in an offshore production well. The result confirms that the formation water saturation calculated by the proposed method agrees well with the actual well production status, further confirming that the proposed method has a promising application in residual oil dynamic monitoring.

Thomas E. Becker - One of the best experts on this subject based on the ideXlab platform.

  • Laboratory Modeling of Mudcake Application and Erosion for Gravel-Pack Design in Horizontal Wells
    SPE Drilling & Completion, 2000
    Co-Authors: Thomas E. Becker, Nicholas H. Gardiner
    Abstract:

    Summary Successful gravel packing of long horizontal sections depends in part on preventing carrier fluid from leaking off to the surrounding permeable reservoir. This requires correctly designed drill-in fluids to apply a thin filter cake, rendering impermeable the sand formation at the wellbore wall. Filter cake must be embedded sufficiently within the formation interstitial space to resist scouring by flowing sand during the gravel-packing operation. This paper summarizes testing using a large-scale laboratory apparatus and procedure designed to test the effectiveness of drill-in fluids planned for use in horizontal wells recently drilled in the Gulf of Mexico. This paper shows the benefits of modeling a horizontal gravel-pack interval before attempting to install the gravel pack. Gravel-packing techniques for long horizontal well sections were evaluated with a laboratory model of a casing/Borehole Annulus. In the horizontal section modeled, permeability is sufficient to interfere with the transportation and distribution of pack sand from total depth to dogleg when positive differential pressure is maintained. The goal of this modeling experiment was to predict whether the formation's permeability at the sandface could be reduced enough to allow successful gravel packing without damaging the formation far beyond the sandface. Gravel-packing technology is well established for near-vertical wells, with off-the-shelf equipment and textbook procedures readily available. The exceptionally long producing intervals in horizontal wells present a greater challenge for gravel packing, however, interval permeability is, by design, continuous. This continuous permeability both enhances well productivity and allows increased wellbore fluid flow into reservoir rock. When the permeable formation absorbs the fluid energy necessary to evenly disperse pack sand throughout the section, sand bridging can result, restricting the flow before the pack sand is fully distributed across the entire interval. The laboratory model simulates the axial flow of drilling and/or completion fluids through an Annulus. The model has an impermeable confining wall (simulating the casing) and a permeable wall (simulating reservoir rock). Recently, it was used for testing the capacity of a drill-in fluid to reduce reservoir near-face permeability, and allow sand propagation throughout a long horizontal interval. Results obtained both in the laboratory and in subsequent field trials validate the use of a drill-in fluid in reducing near-sandface permeability. The procedure has been used successfully on multiple horizontal wells with typical horizontal section lengths of 1,000 to 2,500 ft. Plans are underway to continue the practice in additional wells. Introduction By increasing communication between the well and the payzone, horizontal drilling can increase oilwell production while minimizing operators' per-volume cost. A key decision in constructing a horizontal well is whether to case off the producing zone. If the section is to be cased, three options are available: conventional casing, which must be perforated; a slotted liner; and an uncemented, segmented liner.1 When feasible, an uncased production interval (true openhole completion) is preferred, since steel casing restricts hydrocarbon flow from the reservoir to the well. Operators must consider the obstacles and constraints associated with true openhole completions before making this decision. Such obstacles often include wellbore instability, sand production, and limitations on completion options and future well stimulation. This paper focuses on unconsolidated formations, particularly in sand intervals where the horizontal section must be gravel packed; and demonstrates how a laboratory test apparatus allowed users to predict the success of a gravel-packing strategy for horizontal wells. The gravel-packing process itself is risky.2 For example, the fluid transporting the gravel-packing sand must deliver the sand throughout the intended location; in this case, the entire horizontal interval (Fig. 1). The flow rate selection is constrained by differential pressure integrity (maximum allowable equivalent circulating density), yet it must be high enough to prevent excessive sand settling in the Annulus. For a successful gravel pack, the formation's permeability must be temporarily plugged off so that the transporting fluid remains in the wellbore and does not invade the formation. Forming this plug requires a properly designed drill-in fluid that can quickly create a filter cake that is both impermeable (to plug the formation) and degradable (to restore sandface permeability after the operation). A drill-in fluid's capacity to plug the sandface can be tested in a laboratory. If the drill-in fluid performs as intended, a conventional acid wash or other chemical treatment can remove all remnants of filter cake following the operation. If conditions permit, filter-cake materials in the sandface pores can be forced back through the gravel pack at the onset of production. Experimental Approach A major Gulf of Mexico operator developed plans for a series of horizontal wells for a large field, with horizontal-section lengths exceeding 2,000 ft. The lack of consolidation of the producing sands prohibited true openhole completions without some form of wellbore stability control. To maximize the flow of produced fluid, the operator chose to gravel pack the entire horizontal section instead of casing it. A properly formulated drill-in fluid3 was needed to produce a filter cake that could both plug the highly permeable (300 to 1000 md) sandface, and degrade to restore permeability to the formation after the gravel-packing sand was placed.

  • Laboratory Modeling of Gravel-Packing Process in Horizontal Producing Intervals
    All Days, 1999
    Co-Authors: Thomas E. Becker, Nicholas H. Gardiner
    Abstract:

    Abstract This paper shows the benefits of modeling a horizontal gravelpack interval before attempting to install the gravel pack. Gravelpacking techniques for long horizontal well sections were evaluated with a laboratory model of a casing/Borehole Annulus. In the horizontal section modeled, permeability is sufficient to interfere with the transportation and distribution of pack sand from total depth to dogleg when positive differential pressure is maintained. The goal of this modeling experiment was to predict whether the formation's permeability at the sandface could be reduced enough to allow successful gravel packing without damaging the formation far beyond the sandface. Gravel-packing technology is well established for near-vertical wells, with off-the-shelf equipment and textbook procedures readily available. The exceptionally long producing intervals in horizontal wells present a greater challenge for gravel packing, however. Interval permeability is, by design, continuous. This continuous permeability both enhances well productivity and allows increased wellbore fluid flow into reservoir rock. When the permeable formation absorbs the fluid energy necessary to evenly disperse pack sand throughout the section, sand bridging can result, restricting the flow before the pack sand is fully distributed across the entire interval. The laboratory model simulates the axial flow of drilling and/or completion fluids through an Annulus. The model has an impermeable confining wall (simulating the casing) and a permeable wall (simulating reservoir rock). Recently, it was used for testing the capacity of a drill-in fluid to reduce reservoir nearface permeability, and allow sand propagation throughout a long horizontal interval. Results obtained both in the laboratory and in subsequent field trials validate the use of a drill-in fluid in reducing near-sandface permeability. The procedure has been used successfully on multiple horizontal wells with typical horizontal section lengths of 1,000 to 2,500 ft. Plans are underway to continue the practice in additional wells.

Nicholas Vlachopoulos - One of the best experts on this subject based on the ideXlab platform.

  • Utilizing a novel fiber optic technology to capture the axial responses of fully grouted rock bolts
    Journal of Rock Mechanics and Geotechnical Engineering, 2018
    Co-Authors: Nicholas Vlachopoulos, Daniel Cruz, Bradley Forbes
    Abstract:

    Abstract Rock bolts are one of the primary support systems utilized in underground excavations within the civil and mining engineering industries. Rock bolts support the weakened rock mass adjacent to the opening of an excavation by fastening to the more stable, undisturbed formations further from the excavation. The overall response of such a support element has been determined under varying loading conditions in the laboratory and in situ experiments in the past four decades; however, due to the limitations with conventional monitoring methods of capturing strain, there still exists a gap in knowledge associated with an understanding of the geomechanical responses of rock bolts at the microscale. In this paper, we try to address this current gap in scientific knowledge by utilizing a newly developed distributed optical strain sensing (DOS) technology that provides an exceptional spatial resolution of 0.65 mm to capture the strain along the rock bolt. This DOS technology utilizes Rayleigh optical frequency domain reflectometry (ROFDR) which provides unprecedented insight into various mechanisms associated with axially loaded rebar specimens of different embedment lengths, grouting materials, Borehole Annulus conditions, and Borehole diameters. The embedment length of the specimens was found to be the factor that significantly affected the loading of the rebar. The critical embedment length for the fully grouted rock bolts (FGRBs) was systematically determined to be 430 mm. The results herein highlight the effects of the variation of these individual parameters on the geomechanical responses FGRBs.

  • Utilizing a novel fiber optic technology to capture the axial responses of fully grouted rock bolts
    Elsevier, 2018
    Co-Authors: Nicholas Vlachopoulos, Daniel Cruz, Bradley Forbes
    Abstract:

    Rock bolts are one of the primary support systems utilized in underground excavations within the civil and mining engineering industries. Rock bolts support the weakened rock mass adjacent to the opening of an excavation by fastening to the more stable, undisturbed formations further from the excavation. The overall response of such a support element has been determined under varying loading conditions in the laboratory and in situ experiments in the past four decades; however, due to the limitations with conventional monitoring methods of capturing strain, there still exists a gap in knowledge associated with an understanding of the geomechanical responses of rock bolts at the microscale. In this paper, we try to address this current gap in scientific knowledge by utilizing a newly developed distributed optical strain sensing (DOS) technology that provides an exceptional spatial resolution of 0.65 mm to capture the strain along the rock bolt. This DOS technology utilizes Rayleigh optical frequency domain reflectometry (ROFDR) which provides unprecedented insight into various mechanisms associated with axially loaded rebar specimens of different embedment lengths, grouting materials, Borehole Annulus conditions, and Borehole diameters. The embedment length of the specimens was found to be the factor that significantly affected the loading of the rebar. The critical embedment length for the fully grouted rock bolts (FGRBs) was systematically determined to be 430 mm. The results herein highlight the effects of the variation of these individual parameters on the geomechanical responses FGRBs. Keywords: Fiber optic technology, Fully grouted rock bolts, Load transfer, Stress distributio