Inherently safer sustained casing pressure testing for well integrity evaluation

Rocha-Valadez, Tony; Mentzer, Ray A.; Hasan, A. Rashid; Mannan, M. Sam

doi:10.1016/j.jlp.2014.02.012

Cited by 26 publications

(4 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During multi-stage fracturing, the pressure inside the casing frequently rose and fell, subjecting both the casing and the cement sheath to cyclical loading [25]. Earlier research has shown that while the cement sheath might withstand a static load, it is prone to failure under repeated applications of the same load, typical of the pressure fluctuations experienced in multi-stage fracturing [26].…”

Section: Introductionmentioning

confidence: 99%

Experimental and Numerical Simulation Investigation of Cement Sheath Integrity during Multi-Stage Fracturing in Offshore Tight Oil Reservoir

Wang,

Feng

2024

JMSE

View full text Add to dashboard Cite

The integrity of the cement sheath is susceptible to failure during multi-stage fracturing. In this study, the failure mechanisms of cement sheath integrity during multi-stage fracturing in the A offshore tight oil reservoir wells were investigated. The cement samples were subject to triaxial compression test (TCT), triaxial cyclic loading test (TCLT), and permeability test. A full-scale device was constructed for cement sheath integrity experiments. Additionally, a 3-D finite element model was developed to simulate the interface debonding and the subsequent growth of micro-annuli throughout multi-stage fracturing. The results revealed that TCLT induced cumulative plastic deformation in the cement samples, resulting in a 10.7% decrease in triaxial compressive strength, an 8.3% decrease in elastic modulus, and a 150% increase in permeability. Despite these significant variations, no serious damage was caused to the cement sheath matrix. It was observed that gas leakage occurred at the 8th, 10th, and 14th cycles under cyclic loading with upper limits of 70 MPa, 80 MPa, and 90 MPa, respectively. After 15 cycles, the experimentally measured widths of micro-annuli were 117 μm, 178 μm, and 212 μm, which were in good agreement with simulation results of 130 μm, 165 μm, and 205 μm, respectively. These findings elucidate the causes of cement sheath integrity failure, providing insights into the failure mechanisms of cement sheath integrity during multi-stage fracturing.

show abstract

Section: Introductionmentioning

confidence: 99%

Experimental and Numerical Simulation Investigation of Cement Sheath Integrity during Multi-Stage Fracturing in Offshore Tight Oil Reservoir

Wang,

Feng

2024

JMSE

View full text Add to dashboard Cite

show abstract

“…Xiaoning [9] conducted a casing mechanical analysis and t he safety evaluation of depleted gas storage reservoirs. The safety of an oil well casing string under the condition of sustained casing pressure was evaluated by different methods [10,11]. A stability analysis was conducted by numerical simulation in the case of drilling in deep water gas hydrate-bearing formations [12].…”

Section: Introductionmentioning

confidence: 99%

Mechanical Safety Analysis of the Gas Lift Completion String Used for a High-Pressure Sandwich Layer

Luo

Wen

et al. 2021

Scientia Iranica

View full text Add to dashboard Cite

This study examines the mechanical safety of a gas lift completion string in a certain oilfield, Algeria 438B block, having complex geological characteristics (a high salt and highpressure sandwich). When an annulus is not supported within fluid column after unloading using conventional single-tube gas lift completion with positive lift oil production, inner pressure is so low that the pressure differential between the annulus and external casing is very large, which may damage the casing. Hence, a dual tube completion annulus filled with fluid that can resist pressure was used to overcome this problem, in the adjacent blocks using a gas lift production string with positive and reverse lift oil. However, this technology is complex and characterized by poor system reliability, large construction costs and maintenance difficulty. Considering the three aspects of a casing string, the squeeze strength, tensile strength and internal pressure strength, a gas lift completion string with dual concentric tubes and positive lift was preferably selected under conditions that have been verified as safe for production and a shut-in state. It was shown that this gas lift completion string design is feasible, and has no problem of completion string in adjacent blocks.

show abstract

“…During multi-stage fracturing processes, a large amount of fracturing fluids are injected into the borehole in large pump rate and high pressure [3]. High pressure and complex downhole conditions would increase the risk of casing integrity [4,5]. From 2009 to 2016, 101 fracturing wells have been drilled by Petro-China in Weiyuan-Changning National Shale Gas Demonstration Area, including 90 horizontal wells, while 32 wells of which faced with casing deformation failure problems with 47 deformation points, shown in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Casing Stress during Multi-stage Fracturing Based on Stage Finite Element Method

Guo

Li²,

Liu³

et al. 2018

International Journal of Computational and Experimental Science and Engineering

View full text Add to dashboard Cite

During multi-stage hydro-fracturing operation, casing deformation issues have widely occurred in the Weiyuan-Changning National Shale Gas Demonstration Area, which dramatically reduce the productions of shale gas wells. It is important to access the influence of multiple factors on casing during fracturing operations. In this paper, a stage finite element method is presented to establish three-dimensional physical and finite element casing-cement sheath-formation (CCF) models during volume fracturing processes. It considers the influences of initial stress and displacement state at and near the wellbore. Loads from the initial stress field, fracturing pressure, and transient temperature changes are incorporated in the models. Cement channelling, cement elastic modulus, casing eccentricity, and fracturing pump rate are also the variables taken into account. Sensitivity analyses are conducted to reveal which one has the greatest influence on casing stress. The results indicate that casing stress is highly affected by cement channelling. Low casing stress can be guaranteed by high cement sheath modulus and optimal fracturing pressure. Casing transient temperature is significantly reduced by the large pump rate, then a certain thermal stress generating in the casing. Among all the factors, casing eccentricity has a minor influence on casing stress.

show abstract

Inherently safer sustained casing pressure testing for well integrity evaluation

Cited by 26 publications

References 13 publications

Experimental and Numerical Simulation Investigation of Cement Sheath Integrity during Multi-Stage Fracturing in Offshore Tight Oil Reservoir

Experimental and Numerical Simulation Investigation of Cement Sheath Integrity during Multi-Stage Fracturing in Offshore Tight Oil Reservoir

Mechanical Safety Analysis of the Gas Lift Completion String Used for a High-Pressure Sandwich Layer

Numerical Simulation of Casing Stress during Multi-stage Fracturing Based on Stage Finite Element Method

Contact Info

Product

Resources

About