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The complete paper presents a solution that assesses tight matrices and natural fractures at a level not previously achieved. At the tight-matrix level, advanced nuclear spectroscopy is carried out with a new pulsed-neutron device that achieves simultaneous time- and energy-domain measurements. The complete paper presents a large-scale work flow designed to take a vast amount of data into consideration. The work flow can be scaled for projects of any size, depending on the data available. What Damage Is Wrought by the Rush to Shut In Wells?
This paper presents an analysis of a CO2-foam-injection pilot in the Salt Creek Field, Natrona County, Wyoming. A carbon-dioxide (CO2) -foam enhanced-oil-recovery (EOR) pilot research program has been initiated to advance the technology of CO2 foam for mobility control in a heterogeneous carbonate reservoir. Aqueous foam has been demonstrated to have promise in conformance-control applications. This paper explores the foaming behavior of a CO2-soluble, cationic, amine-based surfactant. A growing chorus of suppliers, researchers, and service companies is persuading US operators to re-examine their use of slickwater in shale plays and consider displacing it with carbon dioxide and nitrogen.
The complete paper presents a large-scale work flow designed to take a vast amount of data into consideration. The work flow can be scaled for projects of any size, depending on the data available. What Damage Is Wrought by the Rush to Shut In Wells? The Permian Basin is now influencing the upstream water market on the way down, while many questions swirl around the implications of unprecedented shut-ins. Country had hoped to boost oil output and bring in much-needed revenues.
Ocampo, Alonso (Gastim Technologies S.A.S.) | Restrepo, Alejandro (Gastim Technologies S.A.S.) | Clavijo, Julian (EQUION ENERGIA LTD.) | Cifuentes, Harold (EQUION ENERGIA LTD.) | Mejia, Juan Manuel (Universidad Nacional de Colombia-Sede Medellín)
This paper presents the development and successful implementation of the Foams technology as an effective EOR mechanism to improve the sweep efficiency of the gas injection in the Piedemonte fields. It also shows the process of optimization of the technology to adapt it to the Piedemonte operating conditions, which is based on massive hydrocarbon gas reinjection, and how this process led us to be at a state of the art position in this technology.
The methodology to adapt and further develop the foam EOR technology in Piedemonte was based on the Capital Value Process (CVP). It starts with a screening exercise, passes through a technical assurance including applicability, fluids compatibility, modeling and coreflooding tests at reservoir conditions. Finally, the specific solution is implemented in the field to confirm effectiveness. Initially the foams were deployed using the conventional Surfactant Alternating Gas (SAG) technique, but then the technology was optimized to better suit the operating conditions of the fields, and the last interventions have been done dispersing the foamer chemical in the gas stream.
This technology has been implemented in most of the fields in the Piedemonte and has proved success since the early implementation pilots in 2011. Implementation started in the Cusiana field, which is a matrix dominated system, and then moved to the naturally fractured and low porosity reservoirs located in the Recetor and Floreña fields. In all the cases, the implementation of foams has rendered positive results reflected in incremental oil production and flattening of the Gas Oil Ratio (GOR) at the influenced producer wells. The new developed dispersed Foams technology has been as effective as the conventional SAG in the jobs performed so far, with the advantages of requiring less surface equipment, and water consumption than SAG jobs. Benefits from Foams implementations so far add up to about 0.65 MM STB.
Main conclusions from this project are i) The foams EOR technology is fully applicable in the Piedemonte fields to improve the gas sweep efficiency and increase final oil recovery. ii) A new foam deployment technique based on the injection of the foamer chemical dispersed in the gas stream was developed, and proved effectiveness at the field.
The work is innovative in two ways: i) Effectiveness of foam as a technology to improve gas sweep efficiency in naturally fractured dominated systems was proved. ii) A new foam deployment technique based on the injection of the foamer chemical dispersed in a non-condensable gas stream was developed. Also this new foam EOR technique can be extrapolated to any other field operated under gas injection.
What Damage Is Wrought by the Rush to Shut In Wells? The Permian Basin is now influencing the upstream water market on the way down, while many questions swirl around the implications of unprecedented shut-ins. Country had hoped to boost oil output and bring in much-needed revenues. This paper describes a coiled tubing gas lift (CTGL) technique successfully used to restart production from two pilot wells in a mature field in Pakistan that had been shut in since 2015. But the flow of ideas continues.
Country had hoped to boost oil output and bring in much-needed revenues. This paper describes a coiled tubing gas lift (CTGL) technique successfully used to restart production from two pilot wells in a mature field in Pakistan that had been shut in since 2015. The Offshore Technology Conference was cancelled for the first time ever due to the COVID-19 pandemic. But the flow of ideas continues. As proof, this curated summary of technical papers highlights unique concepts that might someday reduce the offshore sector’s heavy cost burdens.
To predict liquid-loading tendencies and to identify opportunities for production enhancement, the performance of 150 gas wells was analyzed in two gas fields in India. The XamXung field offshore Sarawak, Malaysia, is a 47-year brownfield with thin remaining oil rims that have made field management challenging. The dynamic oil-rim movement has been a key subsurface uncertainty, particularly with the commencing of a redevelopment project. Production decline with field maturing is a natural phenomenon, but the efforts to mitigate this decline are truly remarkable. Achieving this feat requires not only a deeper understanding of the subsurface process involved but also a total synergy between the various disciplines engaged.
Serious stability problems in boreholes drilled in transversely isotropic rocks have led to several studies related to the combined effect of wellbore trajectory and weakness plane inclination. The stability analyses of wellbores drilled in fields that were affected by slip along the weakness planes were carried out with software based on the weakness plane model. However, this model is discontinuous and cannot capture features of some transversely isotropic rocks. The Hoek & Brown criterion, adapted to anisotropic rocks, is a continuous criterion that can predict mud pressures in a complete range of inclination of the weakness planes. However, this criterion requires a consistent number of triaxial tests, for the determination of the controlling parameters at various inclinations of the weakness planes. Here we propose a novel procedure for the prediction of wellbore pressures in transversely isotropic rocks (typically shales) with the Hoek & Brown criterion coupled with the weakness plane model. The procedure requires a set of uniaxial compression tests performed on rock specimens at different inclinations of the weakness planes and one triaxial test carried out at an inclination of the weakness planes in the range 50 -60 . For our purposes we used the results of lab tests carried out on Opalinus clay.
Beltrán-Jiménez, Katherine (Federal University of Rio de Janeiro) | Lohne, Hans Petter (Norwegian Research Centre/DrillWell) | Ford, Eric Patrick (Norwegian Research Centre/DrillWell) | Skadsem, Hans Joakim (Norwegian Research Centre/DrillWell) | Lourenco de Souza, Marcelo Igor (Federal University of Rio de Janeiro) | Arild, Øystein (Norwegian Research Centre/DrillWell)
In South America, the discussion regarding permanent plug and abandonment (P&A) at the end of the useful life of the fields is relatively recent, but it has become increasingly important due to the maturity of certain oil fields. In Brazil, for example, the Campos, Santos and Espirito Santos Basins alone have 350 temporarily abandoned wells that should be abandoned in the coming decade. The long-term integrity of the wells once plugged and abandoned is, however, not yet considered. There is a need to perform assessments of the risk of leakage, reviewing both the probability of failure of the well barrier elements and the possible magnitude of leakage rates should one or more well barriers be compromised. This article presents a quantitative risk assessment framework that can be used to analyze the probability of barrier failure and potential consequences in terms of leakage rates. Data of a real well is used to quantify the leakage rates after a hypothetic permanent plug and abandonment operation using as reference the plug and abandonment requirements in Brazil and Norway. For both cases, the leakage paths between the reservoir and the wellhead are studied and include: the leakage through bulk cement, cracks/fractures in well barriers elements (impermeable formations, plug, and annular cement) and the presence of micro-annuli. A stochastic framework, using Monte Carlo simulations, is used to propagate uncertainty, yielding probability distributions for leakage rates. As the leakage rates are also a function of time, an analysis considering time-dependent factors such as reservoir re-pressurization is also included. The leakage scenarios for the well is presented considering the P&A requirements included in resolution N 46 (issued by the National Agency of Petroleum, Natural Gas and Biofuels (ANP) in 2016), the guidelines for the abandonment of the Brazilian Petroleum Gas and Biofuels Institute (IBP) and NORSOK D-010. Some requirements, such as plug length and barrier verification methods, are different between these two guidelines. The results are discussed in relation to the P & A requirements and the effect on the total leakage rates for each well case.
Beltrán-Jiménez, Katherine (Federal University of Rio de Janeiro) | Skadsem, Hans Joakim (Norwegian Research Centre) | Gardner, Dave (Norwegian Research Centre) | Kragset, Steinar (Norwegian Research Centre) | Lourenco de Souza, Marcelo Igor (Federal University of Rio de Janeiro)
The cement between the casings and formation is a critical barrier element for ensuring zonal isolation. Shrinkage during curing and mechanical or thermal loads applied during production can compromise the cement and result in fluid migration paths such as micro-annuli. The fluid pressure inside the micro-annulus will cause elastic deformation of the channel walls. This deformation should be accounted for when developing methodologies for interpreting micro-annulus fluid leakage experiments and the application to real well conditions. Full-size test sections have been constructed with known cement defects and leakage properties to investigate barrier verification technologies. A micro-annulus test cell, instrumented with strain and pressure gauges, has been leakage tested. Leakage rates have been correlated to the micro-annulus size using a model coupling micro-annulus pressure to radial deformation of the cement and casing. The semi-analytical model and the predictions are compared to the experimental data. Within the regime of linear elasticity, the radial deformation of the cell wall is proportional to the pressure in the micro-annulus. During leakage testing, the pressure-driven radial deformation of the cell materials is coupled to the variation of the liquid friction pressure gradient along the axial length of the micro-annulus. The pressure gradient is greatest at the outlet of the micro-annulus. The models presented have been used to improve the interpretation of fluid flow during micro-annulus leakage experiments. An improved understanding of fluid leakage mechanisms through micro-annuli can be applied to field cases such as the interpretation and choice of treatment for sustained casing pressure build-up.