scholarly journals Public data from three US states provide new insights into well integrity

2021 ◽  
Vol 118 (14) ◽  
pp. e2013894118
Author(s):  
Greg Lackey ◽  
Harihar Rajaram ◽  
James Bolander ◽  
Owen A. Sherwood ◽  
Joseph N. Ryan ◽  
...  
Keyword(s):  
New Mexico ◽  
Oil And Gas ◽  
The United States ◽  
Gas Leakage ◽  
Integrity Testing ◽  
Well Integrity ◽  
Regional Trends ◽  
Public Data ◽  
Sustained Casing Pressure ◽  
Casing Pressure

Oil and gas wells with compromised integrity are a concern because they can potentially leak hydrocarbons or other fluids into groundwater and/or the atmosphere. Most states in the United States require some form of integrity testing, but few jurisdictions mandate widespread testing and open reporting on a scale informative for leakage risk assessment. In this study, we searched 33 US state oil and gas regulatory agency databases and identified records useful for evaluating well integrity in Colorado, New Mexico, and Pennsylvania. In total, we compiled 474,621 testing records from 105,031 wells across these states into a uniform dataset. We found that 14.1% of wells tested prior to 2018 in Pennsylvania exhibited sustained casing pressure (SCP) or casing vent flow (CVF)—two indicators of compromised well integrity. Data from different hydrocarbon-producing regions within Colorado and New Mexico revealed a wider range (0.3 to 26.5%) of SCP and/or CVF occurrence than previously reported, highlighting the need to better understand regional trends in well integrity. Directional wells were more likely to exhibit SCP and/or CVF than vertical wells in Colorado and Pennsylvania, and their installation corresponded with statewide increases in SCP and/or CVF occurrence in Colorado (2005 to 2009) and Pennsylvania (2007 to 2011). Testing the ground around wells for indicators of gas leakage is not a widespread practice in the states considered. However, 3.0% of Colorado wells tested and 0.1% of New Mexico wells tested exhibited a degree of SCP sufficient to potentially induce leakage outside the well.

scholarly journals A Prediction Model for Sustained Casing Pressure under the Effect of Gas Migration Variety

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Fuping Feng ◽  
Ziyuan Cong ◽  
Wuyi Shan ◽  
Chaoyang Hu ◽  
Maosen Yan ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Prediction Model ◽  
Recovery Time ◽  
Oil And Gas ◽  
Pressure Recovery ◽  
Flow State ◽  
Gas Migration ◽  
Gas Leakage ◽  
Sustained Casing Pressure ◽  
Casing Pressure

Sustained casing pressure (SCP) is a challenge in the well integrity management in oil and gas fields around the world. The flow state of leaked gas will change when migrated up annulus protective fluid. To show the influence of gas migration on casing pressure recovery, a prediction model of SCP based on Reynolds number of bubbles was established. The casing pressure prediction of typical wells and the sensitivity analysis of casing pressure are performed. The results show that the casing pressure recovery time decreases with the increase of cement permeability. However, larger cement permeability has little effect on the casing pressure after stabilization. Increasing the height of annulus protective fluid reduces the stable casing pressure value and shortens the casing pressure recovery time. Compared with the existing models, the results show that the time of casing pressure recovery will be shortened by the change of gas migration, and the effect of bubbles Re < 1 on SCP will be greater. The new model can be used to detect and treat the SCP problem caused by small Reynolds number gas leakage.

Implementation of Factory Cementing Concept in the High-Intensity Drilling Environment of Khazzan, Sultanate of Oman

2021 ◽  
Author(s):  
Emmanuel Therond ◽  
Yaseen Najwani ◽  
Mohamed Al Alawi ◽  
Muneer Hamood Al Noumani ◽  
Yaqdhan Khalfan Al Rawahi ◽  
...  
Keyword(s):  
Shallow Water ◽  
High Intensity ◽  
Sultanate Of Oman ◽  
Cement Slurry ◽  
Short Term ◽  
Lost Circulation ◽  
Well Integrity ◽  
Sustained Casing Pressure ◽  
Zonal Isolation ◽  
Casing Pressure

Abstract The Khazzan and Ghazeer gas fields in the Sultanate of Oman are projected to deliver production of gas and condensate for decades to come. Over the life of the project, around 300 wells will be drilled, with a target drilling and completion time of 42 days for a vertical well. The high intensity of the well construction requires a standardized and robust approach for well cementing to deliver high-quality well integrity and zonal isolation. The wells are designed with a surface casing, an intermediate casing, a production casing or production liner, and a cemented completion. Most sections are challenging in terms of zonal isolation. The surface casing is set across a shallow-water carbonate formation, prone to lost circulation and shallow water flow. The production casing or production liner is set across fractured limestones and gas-bearing zones that can cause A- and B-Annulus sustained casing pressure if not properly isolated. The cemented completion is set across a high-temperature sandstone reservoir with depletion and the cement sheath is subjected to very high pressure and temperature variations during the fracturing treatment. A standardized cement blend is implemented for the entire field from the top section down to the reservoir. This blend works over a wide slurry density and temperature range, has expanding properties, and can sustain the high temperature of the reservoir section. For all wells, the shallow-water flow zone on the surface casing is isolated by a conventional 11.9 ppg lightweight lead slurry, capped with a reactive sodium silicate gel, and a 15.8 ppg cement slurry pumped through a system of one-inch flexible pipes inserted in the casing/conductor annulus. The long intermediate casing is cemented in one stage using a conventional lightweight slurry containing a high-performance lost circulation material to seal the carbonate microfractures. The excess cement volume is based on loss volume calculated from a lift pressure analysis. The cemented completion uses a conventional 13.7 - 14.5 ppg cement slurry; the cement is pre-stressed in situ with an expanding agent to prevent cement failure when fracturing the tight sandstone reservoir with high-pressure treatment. Zonal isolation success in a high-intensity drilling environment is assessed through key performance zonal isolation indicators. Short-term zonal isolation indicators are systematically used to evaluate cement barrier placement before proceeding with installing the next casing string. Long-term zonal isolation indicators are used to evaluate well integrity over the life of the field. A-Annulus and B-Annulus well pressures are monitored through a network of sensors transmitting data in real time. Since the standardization of cementing practices in the Khazzan field short-term job objectives met have increased from 76% to 92 % and the wells with sustained casing pressure have decreased from 22 % to 0%.

Comparative experimental evaluation of drilling fluid contamination on shear bond strength at wellbore cement interfaces

2014 ◽  
Vol 11 (6) ◽  
pp. 597-604 ◽  
Author(s):  
Mileva Radonjic ◽  
Arome Oyibo
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Cement Slurry ◽  
Geothermal Wells ◽  
Sustained Casing Pressure ◽  
Zonal Isolation ◽  
Casing Pressure ◽  
The Impact

Wellbore cement has been used to provide well integrity through zonal isolation in oil and gas wells as well as geothermal wells. Failures of wellbore cement result from either or both: inadequate cleaning of the wellbore and inappropriate cement slurry design for a given field/operational application. Inadequate cementing can result in creation of fractures and microannuli, through which produced fluids can migrate to the surface, leading to environmental and economic issues such as sustained casing pressure, contamination of fresh water aquifers and, in some cases, well blowout. To achieve proper cementing, the drilling fluid should be completely displaced by the cement slurry, providing clean interfaces for effective bond. This is, however, hard to achieve in practice, which results in contaminated cement mixture and poor bonds at interfaces. This paper reports findings from the experimental investigation of the impact of drilling fluid contamination on the shear bond strength at the cement-formation and the cement-casing interfaces by testing different levels of contamination as well as contaminations of different nature (physical vs. chemical). Shear bond test and material characterization techniques were used to quantify the effect of drilling fluid contamination on the shear bond strength. The results show that drilling fluid contamination is detrimental to both cement-formation and cement-casing shear bond strength.

On Liability Issues Concerning Induced Seismicity in Hydraulic Fracturing Treatments and at Injection Disposal Wells: What Petroleum Engineers should know

2015 ◽  
Author(s):  
K.. Hall ◽  
A.. Dahi Taleghani ◽  
N.. Dahi Taleghani
Keyword(s):  
Hydraulic Fracturing ◽  
Seismic Activity ◽  
Oil And Gas ◽  
The United States ◽  
Legal Liability ◽  
Seismic Events ◽  
Public Attention ◽  
Horizontal Drilling ◽  
Public Data ◽  
Induced Seismic Activity

Abstract The rates of oil and natural gas production in the United States have increased dramatically during the past decade, largely due to the use of hydraulic fracturing and horizontal drilling. This has benefitted the U.S. economy and generated hopes that the “shale revolution” could be replicated elsewhere. At the same time, however, public concern has grown regarding potential adverse impacts that fracing or other operations like gas flooding, waterflooding, waste disposal, and other production processes may have. One of the main public concerns relates to induced seismic events – that is, man-made earthquakes. Geologists have concluded that a variety of human activities can induce seismic events. Such operations include the operation of injection disposal wells, though a relatively small fraction of such wells are suspected of inducing seismic activity. Further, available public data shows that, on very rare occasions, hydraulic fracturing itself has caused tangible seismic activity. Although such events have been uncommon, they have attracted significant public attention and strengthened the opponents of oil and gas development. Further, although seismic events induced by oil and gas activity appear to have caused little damage, the potential legal liability could be substantial if such an event ever caused significant damage. Accordingly, industry should give increased attention to minimizing the likelihood of such events. The paper provides context for this issue by briefly reviewing information regarding recent cases of induced seismic activity, current technology for monitoring these events, and the inherent limitations in measurements and interpretation involved in using these techniques. This paper also discusses techniques that operators can use to reduce the likelihood of induced seismic events at hydraulic fracturing sites and at injection disposal wells. These include use of pretreatment geomechanical analyses to assess the likelihood of significant seismic events and, in appropriate circumstances, to guide a modification in perforation clusters design to reduce the likelihood of nearby fault reactivations. Finally, the article provides additional context by discussing relevant laws, including regulatory responses to suspected events of induced seismic activity and the possible legal theories for imposing liability for such events. The new regulations will compel operators to take certain actions and the potential for legal liability may incentivize additional action.

Potentials of Nano-Designed Plugs: Implications for Short and Long Term Well Integrity

2019 ◽  
Author(s):  
Raymos Kimanzi ◽  
Harshkumar Patel ◽  
Mahmoud Khalifeh ◽  
Saeed Salehi ◽  
Catalin Teodoriu
Keyword(s):  
Compressive Strength ◽  
Oil And Gas ◽  
Strength Development ◽  
Cement Slurry ◽  
Preparation Conditions ◽  
Cement System ◽  
Sustained Casing Pressure ◽  
Short And Long Term ◽  
Casing Pressure

Abstract Cement plugs are designed to protect the integrity of oil and gas wells by mitigating movement of formation fluids and leaks. A failure of the cement sheath can result in the loss of zonal isolation, which can lead to sustained casing pressure. In this study, nanosynthetic graphite with designed expansive properties has been introduced to fresh cement slurry. The expansive properties of nanosynthetic graphite were achieved by controlling the preparation conditions. The material was made from synthetic graphite and has a surface area ranging from 325–375 m2/gram. Several tests including compressive strength, rheology, and thickening time were performed. An addition of 1% nanosynthetic graphite with appropriate reactivity was sufficient to maintain expansion in the cement system, leading to an early compressive strength development. It has excellent thermal and electrical conductivity and can be used to design a cement system with short and long-term integrity. Rheology and thickening time tests confirmed its pumpability. Controlling the concentration of the additive is a promising method that can be used to mitigate gas migration in gas bearing and shallow gas formations.

scholarly journals A Comparative Analysis of Texas and New Mexico Oil and Gas Laws from a Title Examiner's Perspective

2020 ◽  
Vol 6 (3) ◽  
Author(s):  
Carly Hewett
Keyword(s):  
United States ◽  
New Mexico ◽  
Comparative Analysis ◽  
Oil And Gas ◽  
Case Law ◽  
The United States ◽  
Regulatory Body ◽  
Gas Laws ◽  
Well Spacing ◽  
Oil Gas

The statutory framework surrounding oil and gas law and the related title issues in Texas and New Mexico, while similar in many instances, do have some notable differences. New Mexico case law is very limited, which could be due to a variety of reasons, including a smaller state population and the fact that New Mexico and the United States own much of New Mexico’s oil and gas productive acreage. Therefore, practitioners often look to other jurisdictions, including Texas, for guidance. Texas’s secondary authority is also better developed with its own adopted title standards.1 New Mexico does not have such guidance. This Article will focus on the distinctions between the oil and gas laws and the passage of title in Texas and New Mexico from a title examiner’s perspective. Both states do have a regulatory body—the Texas the Railroad Commission (“TXRRC”) and the New Mexico Oil Conservation Division (“NMOCD”)2—that oversees oil, gas, and other mineral activities by regulating activities such as well spacing, allowables, and pooling.

Inherently safer sustained casing pressure testing for well integrity evaluation

2014 ◽  
Vol 29 ◽  
pp. 209-215 ◽  
Author(s):  
Tony Rocha-Valadez ◽  
Ray A. Mentzer ◽  
A. Rashid Hasan ◽  
M. Sam Mannan
Keyword(s):  
Pressure Testing ◽  
Well Integrity ◽  
Sustained Casing Pressure ◽  
Casing Pressure

Annular Barrier as an Alternative to Squeezes in Challenging Wells: Technology Review and Case Histories

2016 ◽  
Author(s):  
Joseph Bagal ◽  
Gbenga Onadeko ◽  
Paul Hazel ◽  
Vibjørn Dagestad
Keyword(s):  
Hydraulic Pressure ◽  
Case Histories ◽  
Regulatory Requirements ◽  
Pump Failure ◽  
Advantages And Disadvantages ◽  
Second Stage ◽  
Well Integrity ◽  
Open Hole ◽  
Sustained Casing Pressure ◽  
Casing Pressure

ABSTRACT The drilling industry has always relied on cement as a primary barrier. Although the cement represents about 5% of the well cost, when squeezes are required, cementing averages 17% of the well cost. Only 50% of the squeezes achieve the objective of establishing a barrier for well integrity. A little bit more than half of the failures can be attributed to operational challenges (pump failure, cement contamination), or design oversights (cement recipe, centralizers). However there are still cement failures with perfect design and field execution. These failures typically exhibit some of the following characteristics: high deviation, high pressure, washouts, natural fractures, long casing section, heterogeneous sands. For these specific conditions, it is beneficial to add an assurance that would maintain the integrity of the well even in case of bad cement. Some of the assurances used include port collars, external casing packers (ECP) and swell packers. Port collars allow a squeeze above the first stage cement, while ECP serves as a base for a second stage cement, and swell packers provides a baffle for sustained casing pressure. A more recent technology is the well annular barrier that can form a combined barrier with cement, and can also be used as a stand-alone primary barrier. The well annular barrier is a metal-expandable barrier that is expanded with hydraulic pressure. It is full bore, highly customizable, and qualified to ISO 14310. The metallurgy allows the packer to shape fit into either an open hole with irregular geometry or inside a casing to preclude annular pressure build up by giving a life-of-well reliable seal. The well annular barrier has been deployed in a variety of wells to achieve well integrity with and without cement, protect the B-annulus from sustained casing pressure, or serve as a barrier between reservoirs that cannot be commingled. This paper performs a review of the technologies used for cement assurance, their advantages and disadvantages. Case histories of well annular barrier deployments are presented, including a case where the well annular barrier was used as a stand-alone well barrier element without the need for dispensation. This paper also discusses how the well annular barrier fits into the regulatory requirements for well construction providing to the drilling industry an alternative to cement for the purpose of well integrity.

Robust Leakage Modeling for Plug and Abandonment Applications

2019 ◽  
Author(s):  
Mustafa Al Ramadan ◽  
Saeed Salehi ◽  
Catalin Teodoriu
Keyword(s):  
Oil And Gas ◽  
Pore Space ◽  
Differential Pressure ◽  
Cement Slurry ◽  
High Pressure And Temperature ◽  
Gas Leakage ◽  
Fluid Leakage ◽  
Well Integrity ◽  
Cement Plug

Abstract Oil and gas wells that require to be shut off forever, after depleting their reserves, need to be plugged and abandoned. Plug and Abandonment (P&A) operations induce many arduous challenges worldwide. The aim of P&A is to isolate and prevent fluid leakage in the wellbore in such a way that all fluids are contained in their formation for an undefined time. Failure of P&A in isolating and preventing fluid leakage can jeopardize the well integrity. Cement plugs that are used in this operation play a crucial role in maintaining the well integrity. Cement is considered as a porous medium that has an ultra-low permeability that can be achieved when some additives are used in the cement slurry to reduce its permeability and pore space. The cement plug may deteriorate with time under harsh downhole conditions, such as high pressure and temperature and exposure to different fluids. Cement plug deterioration will result in increasing the cement permeability or the overall permeability by creating channels or microannuli. In this study, several scenarios are presented for gas leakage through cement plugs. In these leakage scenarios, the differential pressure across the cement plug was varied. The aim of generating these scenarios is to investigate the current required cement plug length. In each scenario, four different permeability values were used to assess the risk associated with each value. In addition, the cement plug length was varied to investigate how the cement plug length is going to help ensure good well integrity. The leakage scenarios presented revealed that longer cement plugs have a longer leakage time. In addition, the results show an increase of leakage time as microannulus gap permeability decreases. Differential pressure exerted on the cement plug have a strong effect on the leakage time. To achieve a long term well integrity in P&A phase, an ultra-low permeable cement plug with excellent bonding, longer cement plug, and a lower differential pressure across the cement must be considered.

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