How To Prevent Loss of Zonal Isolation Through a Comprehensive Analysis of Microannulus Formation

Bois, Axel-Pierre; Garnier, André; Rodot, Francois; Sain-Marc, Jeremie; Aimard, Nicolas

doi:10.2118/124719-pa

Cited by 157 publications

(27 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Poor primary cement can occur by the development of fluid channels, casings that are not centered in the well, poor bonding and shrinkage, and losses of cement into the surrounding rock (68). Well operations can also damage cement through temperature and pressure changes (52,69).…”

Section: Mechanisms Of Wellbore-integrity Failurementioning

confidence: 99%

The Environmental Costs and Benefits of Fracking

Jackson

Vengosh

Carey

et al. 2014

Annu. Rev. Environ. Resour.

376

203

View full text Add to dashboard Cite

Unconventional oil and natural gas extraction enabled by horizontal drilling and hydraulic fracturing (fracking) is driving an economic boom, with consequences described from "revolutionary" to "disastrous." Reality lies somewhere in between. Unconventional energy generates income and, done well, can reduce air pollution and even water use compared with other fossil fuels. Alternatively, it could slow the adoption of renewables and, done poorly, release toxic chemicals into water and air. Primary threats to water resources include surface spills, wastewater disposal, and drinking-water contamination through poor well integrity. An increase in volatile organic compounds and air toxics locally are potential health threats, but the switch from coal to natural gas for electricity generation will reduce sulfur, nitrogen, mercury, and particulate air pollution. Data gaps are particularly evident for human health studies, for the question of whether natural gas will displace coal compared with renewables, and for decadal-scale legacy issues of well leakage and plugging and abandonment practices. include data for (a) estimated ultimate recovery (EUR) of unconventional hydrocarbons, (b) the potential for further reductions of water requirements and chemical toxicity, (c) whether unconventional resource development alters the frequency of well integrity failures, (d ) potential contamination of surface and ground waters from drilling and spills, (e) factors that could cause wastewater injection to generate large earthquakes, and ( f ) the consequences of greenhouse gases and air pollution on ecosystems and human health.

show abstract

Section: Mechanisms Of Wellbore-integrity Failurementioning

confidence: 99%

The Environmental Costs and Benefits of Fracking

Jackson

Vengosh

Carey

et al. 2014

Annu. Rev. Environ. Resour.

376

203

View full text Add to dashboard Cite

show abstract

“…Accounting for microannuli in a risk assessment is a challenge: They can appear when pressure (or temperature) in the well drops or formation pressure is increased, so cement-evaluation logs should, in theory, be repeated after every change in well use to confirm their existence, an expensive and logistically problematic option. Alternatively, one can use advanced thermomechanical models of cement-sheath behavior to predict the presence of microannuli (Bois et al 2011(Bois et al , 2012. Within the context of a basin-scale risk assessment, with its time and information constraints, however, there are substantial benefits in adopting a simplified model based on that in Lecampion et al (2013).…”

Section: Resultsmentioning

confidence: 99%

An Evidence-Based Approach to Well-Integrity Risk Management

Loizzo

Bois²,

Etcheverry³

et al. 2015

SPE Economics &Amp; Management

Self Cite

View full text Add to dashboard Cite

The Paris basin (France) is a particularly challenging setting for oil production: Besides lying under a metropolis of 12-million people, it is also exploited for low-temperature geothermal energy and is crossed by a deep, high-quality drinking-water aquifer of strategic importance, the Albian-Neocomian. Vermilion, the biggest producer in the area, undertook in 2012 a basinwide well-integrity risk-management project with the goal of understanding and minimizing the risk of freshwater-aquifer pollution.The Paris basin operations include 20 fields, for a total of 289 active wells, more than half of which were drilled in the 1980s. The objectives of the leakage risk assessment are twofold: First, identify high-risk scenarios and "must act" wells that require immediate intervention; second, adopt lean (i.e., eliminating waste) prevention and mitigation measures that satisfy the local regulator.The risk-assessment methodology is based on scenarios (i.e., ways in which the hazards, brines or hydrocarbons, can cause damage to targets, the freshwater aquifers). Each scenario involves the failure of a number of barriers with the function to prevent or mitigate damage. In this approach, evidence from in-depth failure analysis is used to build and calibrate scenarios, as well as to validate degradation mechanisms and understand their dynamics. Evidence considered is not limited to drilling reports and wireline logs, but includes all observations, measurements, and weak signals that one can use to test assumptions on the presence, absence, or aging of well integrity. Evidence-based scenarios are complemented by known failure mechanisms, thus reducing the risk of "black swans," very improbable but catastrophic events, even though their probability is constrained by observed behavior during the 4,000 well years of operations in the basin.The criticality (product of probability and severity) of each applicable scenario is then computed by use of an exhaustive database of the characteristics of each well, resulting in a complete risk profile for the basin. The risk-assessment process revealed that casing corrosion caused by brine injection is the biggest driver of well-integrity risk; it also allowed tailoring effective prevention and mitigation actions: For instance, the criticality of scenarios is reduced to an acceptable level if the time between tubing failure and injection stop is kept to 3 months or less. Furthermore, the analysis helps define the role of periodic logging and thus reduce possible waste (i.e., actions that do not contribute to understanding, preventing, or mitigating risk).The evidence-based approach, since applied to another French basin, has proved effective for managing risk at the basin level, by cutting a middle way between universal checklists and the excessively narrow focus of well-by-well analysis: The former are too large and hazy and may hide real dangers among hardly applicable generalities, whereas the latter tends to be expensive and unsystematic and misses recurring patterns. Heavy-duty analy...

show abstract

“…As described in the previous section, cement sheaths typically fail because of volumetric instability and imposed tensile stresses beyond the tensile strength of the cement sheath. (Shadravan et al, 2014;Williams et al, 2011) Pressure increase is more damaging because the fluid injection lasts from minutes to hours (Thiercelin et al, 1998) Several have suggested requirements to tensile strength, Young's modulus, and other mechanical properties of the cement sheath to provide a long-term zonal isolation through long-term stress evaluation (Bois et al, 2011;Bois et al, 2012;Roy-Delage et al, 2000;Saint-Marc et al, 2008;Stiles and Hollies, 2002). Thiercelin et al (1998) analyzed different stress conditions in oil wells which were applicable for most types of loading.…”

Section: Requirements To Cement Systems To Provide Long-term Zonal Ismentioning

confidence: 99%

Cement sheath modification using nanomaterials for long-term zonal isolation of oil wells: Review

Jafariesfad

Geiker

Gong

et al. 2017

Journal of Petroleum Science and Engineering

View full text Add to dashboard Cite

Well cementing is an important operation during drilling and completion of oil wells. The cement sheath must maintain well integrity behind the casing and provide long-term zonal isolation to ensure safety and prevent environmental problems. Despite recent technological advancement in smart polymeric materials, fibers and self-healing materials, it is still a big challenge to provide adequate long-term zonal isolation in severe oil well conditions. This review provides an overview of challenges faced in oil wells compromising the long-term ability of the cement sheath to provide zonal isolation. Factors controlling the long-term performance of cement sheath are discussed, in terms of shrinkage, tensile strength and flexibility. The use of nanomaterials as cement additive to fabricate flexible, high-tensile strength, and low-shrinkage cement system are reviewed.Introduction of nanomaterials into the cement system is a promising approach to design a sealant for the entire life of the well, thereby avoiding potential remedial costs and environmental impacts.

show abstract

How To Prevent Loss of Zonal Isolation Through a Comprehensive Analysis of Microannulus Formation

Cited by 157 publications

References 40 publications

The Environmental Costs and Benefits of Fracking

The Environmental Costs and Benefits of Fracking

An Evidence-Based Approach to Well-Integrity Risk Management

Cement sheath modification using nanomaterials for long-term zonal isolation of oil wells: Review

Contact Info

Product

Resources

About