The margin between pore pressure and fracture gradient can be as low as 0.2 in offshore wells, particularly deep water wells. Slim-hole and tight-annulus wells can create or compound the challenges of already narrow pressure margins. Formations with low fracture gradients can break down under the hydrostatic pressure of the drilling fluid or cement column and can result in lost circulation. The probability of maintaining circulation throughout cement placement operations can be higher when employing options such as lightweight systems and/or alternative placement methods.
Narrow Pressure Margin - Alternative Cement Placement Methods
DeepAssurance™ Cementing Solution Suite As water depths and distance to shore increase, operational challenges and budget pressures intensify. Halliburton has the capability to help with dual-gradient cementing and managed pressure cementing as well as puddle jobs (running a liner into a column of cement already in the wellbore), tack and squeeze cementing and reverse-circulation cementing.
Narrow Pressure Margin – Casing Equipment
DeepAssurance™ Cementing Solution Suite Specific considerations need to be given to casing standoff and casing run-in speeds. Providing for optimized standoff of the casing helps to enable complete coverage of the slurry system for successful zonal isolation. Halliburton offers a wide variety of centralizer choices, some that dramatically reduce frictional pressures and create unimpeded fluid-flow paths. Without the use of automated casing fill systems, expensive rig time is lengthened due to significantly slower run-in speeds in order to avoid the plunger-effect that can damage the formation and cause lost circulation. Halliburton offers an entire casing string, from cement head to float shoe, helping operators lower equivalent circulating densities thus reducing rig time while running and landing casing to depth efficiently. This string is designed to integrate seamlessly with Halliburton’s VersaFlex® expandable liner hanger.
Narrow Pressure Margin – Fluid Systems
DeepAssurance™ Cementing Solution Suite Velocity and flow rate of spacers and cements during placement affect the probability of efficient displacement of preceding wellbore and annular fluids, which in turn affects complete cement placement. However, these variables should be managed carefully in a narrow pressure margin well. While pipe movement such as rotation and reciprocation can help facilitate displacement / placement dynamics, when wellbores present narrow pressure margins, or when well trajectories are highly deviated and/or slim hole, pipe rotation may not be possible. Thus, fluid densities and rheological hierarchy, among many other variables that influence a successful cementing operation, need to be thoroughly evaluated.
Narrow Pressure Margin – Lost Circulation Materials
DeepAssurance™ Cementing Solution Suite Lost circulation is the partial or complete loss of drilling fluid and/or cement slurry to the formation during drilling or cementing operations or both. This can be brought on by natural or induced causes. Natural causes include situations such as naturally fractured formations or unconsolidated zones. Induced losses occur when the hydrostatic fluid column pressure exceeds the fracture gradient of the formation and the formation pores break down enough to receive rather than resist the fluid. When lost circulation occurs, it can provoke new requirements of time and mud or cement - and add substantially to the overall cost of a well.
Typical ways to address lost circulation during cementing operations is with bridging or plugging material, the use of rapid-set or thixotropic cement, or with lightweight cement systems.
•Reduce the slurry density (lightweight cement)
•Add a bridging or plugging material
Narrow Pressure Margin – Software Systems / Design, Plan
DeepAssurance™ Cementing Solution SuiteHalliburton provides simulations that can model three-dimensional displacement and mud erodibility based on fluid volumes and compressibility, rheological hierarchy, pump rates and wellbore geometry. These variables are vitally important to preparing the wellbore to receive cement and achieve a successful primary cementing operation and zonal isolation for the life of the well. Halliburton offers the ability to run the entire cementing operation in the risk-free environment of a virtual simulation, providing empirical data to answer questions before the job is run.
For more specifications:
http://www.halliburton.com/en-US/ps/cementing/deep-water-cementing/narrow-pressure-margin.page?node-id=hsx1lheh
Narrow Pressure Margin - Alternative Cement Placement Methods
DeepAssurance™ Cementing Solution Suite As water depths and distance to shore increase, operational challenges and budget pressures intensify. Halliburton has the capability to help with dual-gradient cementing and managed pressure cementing as well as puddle jobs (running a liner into a column of cement already in the wellbore), tack and squeeze cementing and reverse-circulation cementing.
Narrow Pressure Margin – Casing Equipment
DeepAssurance™ Cementing Solution Suite Specific considerations need to be given to casing standoff and casing run-in speeds. Providing for optimized standoff of the casing helps to enable complete coverage of the slurry system for successful zonal isolation. Halliburton offers a wide variety of centralizer choices, some that dramatically reduce frictional pressures and create unimpeded fluid-flow paths. Without the use of automated casing fill systems, expensive rig time is lengthened due to significantly slower run-in speeds in order to avoid the plunger-effect that can damage the formation and cause lost circulation. Halliburton offers an entire casing string, from cement head to float shoe, helping operators lower equivalent circulating densities thus reducing rig time while running and landing casing to depth efficiently. This string is designed to integrate seamlessly with Halliburton’s VersaFlex® expandable liner hanger.
Narrow Pressure Margin – Fluid Systems
DeepAssurance™ Cementing Solution Suite Velocity and flow rate of spacers and cements during placement affect the probability of efficient displacement of preceding wellbore and annular fluids, which in turn affects complete cement placement. However, these variables should be managed carefully in a narrow pressure margin well. While pipe movement such as rotation and reciprocation can help facilitate displacement / placement dynamics, when wellbores present narrow pressure margins, or when well trajectories are highly deviated and/or slim hole, pipe rotation may not be possible. Thus, fluid densities and rheological hierarchy, among many other variables that influence a successful cementing operation, need to be thoroughly evaluated.
Narrow Pressure Margin – Lost Circulation Materials
DeepAssurance™ Cementing Solution Suite Lost circulation is the partial or complete loss of drilling fluid and/or cement slurry to the formation during drilling or cementing operations or both. This can be brought on by natural or induced causes. Natural causes include situations such as naturally fractured formations or unconsolidated zones. Induced losses occur when the hydrostatic fluid column pressure exceeds the fracture gradient of the formation and the formation pores break down enough to receive rather than resist the fluid. When lost circulation occurs, it can provoke new requirements of time and mud or cement - and add substantially to the overall cost of a well.
Typical ways to address lost circulation during cementing operations is with bridging or plugging material, the use of rapid-set or thixotropic cement, or with lightweight cement systems.
•Reduce the slurry density (lightweight cement)
•Add a bridging or plugging material
Narrow Pressure Margin – Software Systems / Design, Plan
DeepAssurance™ Cementing Solution SuiteHalliburton provides simulations that can model three-dimensional displacement and mud erodibility based on fluid volumes and compressibility, rheological hierarchy, pump rates and wellbore geometry. These variables are vitally important to preparing the wellbore to receive cement and achieve a successful primary cementing operation and zonal isolation for the life of the well. Halliburton offers the ability to run the entire cementing operation in the risk-free environment of a virtual simulation, providing empirical data to answer questions before the job is run.
For more specifications:
http://www.halliburton.com/en-US/ps/cementing/deep-water-cementing/narrow-pressure-margin.page?node-id=hsx1lheh
