Reservoir Monitoring Activities for Co2 Wag Pilots

2021 ◽  
Author(s):  
Saeeda Hasan ◽  
Manjit Kumar ◽  
Moza Abdelrahman ◽  
Arit Igogo ◽  
Yatindra Bhushan ◽  
...  
Keyword(s):  
Flow Line ◽  
Surface Flow ◽  
Sampling Point ◽  
Carbon And Oxygen Isotopes ◽  
Horizontal Section ◽  
Fluid Saturation ◽  
Carbon And Oxygen Isotope ◽  
Reservoir Monitoring ◽  
Monitoring Activities ◽  
Water Cut

Abstract Two CO2 WAG Pilots are in progress in an Abu Dhabi Oil Reservoir. Each pilot has one horizontal producer and two horizontal injectors along with 2 vertical pilot observers to monitor the movement of flood front away from the injectors. The pilots are being monitored based on a detailed reservoir-monitoring plan. The paper discusses in detail various activities and the results related to the pilot monitoring. Methods, Procedures, Process The wells are being tested for oil rate, water cut, GOR on a daily basis using MPFM. For calibration purposes portable test separators are used every quarter to validate the rate, water cut and GOR measurements. Separator PVT samples from pilot wells are collected every quarter for PVT analysis. In addition PVT samples are also collected from the pilot wells and nearby wells every month from the sampling point near MPFM to monitor the CO2 content in the produced gas. Online CO2 analyzer is fitted on the surface flow line connecting pilot wells to the RDS to provide continuous measurement of CO2 in the produced fluid. Produced water is also sampled for detailed compositional analysis. Different gas and water tracers have been injected through the pilot injectors to trace the movement and breakthrough of injected fluids into the pilot producers. Sampling and analysis for tracer is carried out on a regular basis. Carbon and oxygen Isotope analysis for produced and injected CO2 gas is also carried out in order to monitor the breakthrough of injected CO2 into the pilot producers. There is a good difference in the carbon and oxygen isotopes of injected CO2 and the CO2 present in the reservoir. To monitor the changes in water and gas saturation with time across different layers a set of Pulsed neutron (RAS) logs are run in the observers on regular basis. PLT logs are run in the injectors and producers to check the distribution and conformance of the produced and injected fluids along the horizontal wellbore. Walk away VSP surveys are being carried out on regular intervals for one pilot to monitor the injected fluids distribution in the pilot area. The paper describes all these reservoir monitoring activities in detail. Results, Observations, Conclusions Analysis of Carbon oxygen RST logs are helpful for tracking fluid saturation changes and CO2 movement across the logged intervals. The RST logs in the observers demonstrate good sweep across different layers of the reservoir. Analysis of CO2 in produced gas has resulted into correctly pointing out the timing of CO2 breakthrough in the producers. It is well supported by the CO2 isotopes analysis for the injected and produced CO2 through pilot producer and nearly producers. The tracer analysis results show clearly the injector from where the injected CO2 has reached the producers. The PLT logs demonstrate good conformance for CO2 and water injection across the horizontal section in the injectors. All these monitoring activities provide a good source of data for further analysis and improved understanding of the pilots. Novel/Additive Information The paper discusses the usefulness of different reservoir monitoring tools for improved understanding of the pilots, which will be used as a basis for implementing CO2 WAG for the full area development.

scholarly journals On the limit to resolution and information on basal properties obtainable from surface data on ice streams

2008 ◽  
Vol 2 (2) ◽  
pp. 167-178 ◽  
Author(s):  
G. H. Gudmundsson ◽  
M. Raymond
Keyword(s):  
Flow Line ◽  
Estimation Method ◽  
Optimal Estimation ◽  
Surface Flow ◽  
Ice Thickness ◽  
Ice Streams ◽  
Statistical Estimates ◽  
Surface Data ◽  
Highly Sensitive ◽  
Surface Measurements

Abstract. An optimal estimation method for simultaneously determining both basal slipperiness and basal topography from variations in surface flow velocity and topography along a flow line on ice streams and ice sheets is presented. We use Bayesian inference to update prior statistical estimates for basal topography and slipperiness using surface measurements along a flow line. Our main focus here is on how errors and spacing of surface data affect estimates of basal quantities and on possibly aliasing/mixing between basal slipperiness and basal topography. We find that the effects of spatial variations in basal topography and basal slipperiness on surface data can be accurately separated from each other, and mixing in retrieval does not pose a serious problem. For realistic surface data errors and density, small-amplitude perturbations in basal slipperiness can only be resolved for wavelengths larger than about 50 times the mean ice thickness. Bedrock topography is well resolved down to horizontal scale equal to about one ice thickness. Estimates of basal slipperiness are not significantly improved by accurate prior estimates of basal topography. However, retrieval of basal slipperiness is found to be highly sensitive to unmodelled errors in basal topography.

Paleoenvironmental Traces of Carbon and Oxygen Isotopes in Carbonate Rocks: An Example From Dengying Formation in Xichuan Area, Henan Province

2020 ◽  
Author(s):  
Lan Zhang ◽  
Hong Xie ◽  
Qingguang Li ◽  
Zhenghao Lu ◽  
Yang Bai ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Carbonate Rocks ◽  
Isotope Composition ◽  
Salinity Range ◽  
Carbon And Oxygen Isotopes ◽  
Accurate Analysis ◽  
Average Value ◽  
Dengying Formation ◽  
Three Samples ◽  
Carbon And Oxygen Isotope

Abstract The carbon and oxygen isotope composition of carbonate rocks is an important index for accurate analysis of the paleo-sea environment, which depends on Mn/Sr, δ 18 O > -10‰, correlativity of δ 13 C and δ 18 O and “age effect” of δ 18 O. This study reports carbon and oxygen isotope data of carbonate rocks from the Dengying Formation in the Xichuan area. δ 13 C values range -1.58‰ to 3.76‰, with an average value of 1.55‰, and δ 18 O values are -14.91‰ to -1.88‰, with an average value of -6.95‰. The δ 18 O values of three samples are less than -10‰, so they are excluded and taken to be correlative with the cracking of the Rodinia supercontinent during the Neoproterozoic. The paleotemperature range 7.40°C to 35.05°C, with an average value of 21.09°C. Paleo-salinity range 8.38‰ to 19.30‰, with an average value of 13.89‰. Z values range 127.80 to 135.03 and thus all exceeded 120, with an average value of 131.25. These calculations indicate that the Xichuan area had deposited marine carbonate rocks, with the hot and dry tropical monsoon climate, and a transgressive process overall during the Dengying age.

scholarly journals 14C Dating of Fire-Damaged Mortars from Medieval Finland

Radiocarbon ◽  
2012 ◽  
Vol 54 (3-4) ◽  
pp. 915-931 ◽  
Author(s):  
Alf Lindroos ◽  
Lior Regev ◽  
Markku Oinonen ◽  
Åsa Ringbom ◽  
Jan Heinemeier
Keyword(s):  
14C Dating ◽  
Carbon And Oxygen Isotopes ◽  
Fire Event ◽  
Oxygen Isotope Ratios ◽  
Hydrolysis Process ◽  
Carbon And Oxygen Isotope ◽  
Different Temperatures ◽  
Long Time ◽  
Original Construction ◽  
Soluble Carbonate

This study focuses on radiocarbon dating of mortars that have withstood city fires and display visible fire damage effects. Some fire-damaged and undamaged original Medieval mortars from the same site have also been tested. The mortars were heated at different temperatures and then analyzed using the same preparation procedures as in 14C dating of mortars to see what kind of changes the heating would introduce to the mineralogy, chemistry, and the carbon and oxygen isotope ratios. We found that decarbonation during heating starts at ∼600 ° and recarbonation starts as soon as the temperature drops. Already after a few days, most of the lost CO2 has been replaced with atmospheric CO2. The renewed carbonates are readily soluble in the acid hydrolysis process and their carbon and oxygen isotopes have a light signature. Fire-damaged historical mortars display the same features. If a long time has elapsed between hardening of the original mortar and the fire, the new carbonates have 14C concentrations that point to the fire event rather than to the building event. In several cases, the fire-damaged mortars have an easily soluble carbonate fraction with a 14C age that could be related to a major fire event, but still most of the soluble carbonate yields a 14C age that seems like a reasonable age for the original construction.

Effect of Sand Content on the Filter Cake Properties and Removal During Drilling Maximum Reservoir Contact Wells in Sandstone Reservoir

2015 ◽  
Vol 138 (3) ◽  
Author(s):  
Badr S. Ba geri ◽  
Mohamed Mahmoud ◽  
Saleh. H. Al-Mutairi ◽  
Abdulazeez Abdulraheem
Keyword(s):  
Calcium Carbonate ◽  
Filter Cake ◽  
Flow Line ◽  
Drilling Fluid ◽  
Horizontal Section ◽  
Fluid Properties ◽  
Porosity And Permeability ◽  
Sand Particles ◽  
Sandstone Reservoir ◽  
Sandstone Formation

The drilling mud program contains many tests such as filtration rate and filter cake properties to select the proper drilling fluid additives that yield the standard ranges of the viscosity, filtration rate, etc. However, the physical and chemical changes in the mud composition during the mud circulating will cause changes to the filter cake properties. The changes in the filter cake properties should be considered in the mud design program to prevent the problems associated with the change in the drilling fluid properties. For long horizontal wellbores penetrating plastic formations, the two sources of solids in filter cake are drilling chemical additives and formation cuttings (sand particles in the case of sandstone reservoir). This study focuses on the effect of introducing sand particles from the drilled—formations on the filter cake properties. Real drilling fluid samples from the field were collected at different location during drilling a 3600 ft of the horizontal section of a sandstone formation. Calcium Carbonate (CaCO3) was used as weighting material in this filed. The drilling fluid samples were collected at two different points: the flow line coming from the well after shale shaker and the flow line going to the well to verify the effect of separation stages on filter cake properties. The primary drilling fluid properties of the collected samples were measured such as density and rheological parameters. High pressure high temperature (HPHT) filter press was used to perform the filtration and filter cake experiments at 300 psi differential pressure and room temperature (25 °C). The mineralogy of the external filter cake formed by fluid loss cell is determined using SEM (scanning electron microscopy) and XRD (X-ray diffraction). Finally, solubility test was conducted to evaluate the effect of sand particles on filter cake removal (containing Calcium Carbonate as weighting material) using chelating agent: glutamic diacetic acid (GLDA) at pH 4. The results showed that for long horizontal sections, the effect of introducing sand particles to the composition of the filter cake can cause significant change to the properties of filter cake such as mineralogy, thickness, porosity, and permeability. For instant the thickness of filter cake increased about 40% of its original thickness when drilling sandstone formation in horizontal well due to fine sand particle settling. The filter cake porosity and permeability increment in the first 2000 ft part of the horizontal section was observed clearly due to the irregular shape of the drilling particles. However for the points after the first 2000 ft of horizontal lateral, the porosity and permeability almost remained constant. Increasing the sand content up to 20% degrade the dissolution rate of calcium carbonate in the GLDA (pH = 3.8) to 80% instead of 100%.

The utility of stable isotopic signatures in coral skeletons

1996 ◽  
Vol 1 ◽  
pp. 249-291 ◽  
Author(s):  
Peter K. Swart ◽  
Jim J. Leder
Keyword(s):  
Isotopic Composition ◽  
Dissolved Inorganic Carbon ◽  
Carbon Isotopic Composition ◽  
Oxygen Isotopic Composition ◽  
Stable Carbon ◽  
Carbon And Oxygen Isotopes ◽  
Coral Skeletons ◽  
Carbon And Oxygen Isotope ◽  
Oxygen Isotopic ◽  
Zooxanthellate Corals

There is a fundamental ecologic differentiation between zooxanthellate and non-zooxanthellate corals. This paper reviews factors which govern the stable carbon and oxygen isotopic composition of these groups of corals. Although the stable carbon and oxygen isotope compositions of coral skeletons are strongly influenced by environmental and physiological factors, the precise mechanisms remain a matter of debate. In particular the oxygen isotopic composition is known to be governed by the temperature and the oxygen isotopic composition of the water and perhaps also by kinetic factors. In contrast the carbon isotopic composition is controlled by a combination of photosynthesis, respiration, autotrophy, heterotrophy, and the isotopic composition of dissolved inorganic carbon. Using a combination of carbon and oxygen isotopes it is possible to distinguish zooxanthellate from non-zooxanthellate corals.

Stratigraphic variations in carbon and oxygen isotopes in the dolostone of the Carswell Formation (Proterozoic) of northern Saskatchewan

1989 ◽  
Vol 26 (11) ◽  
pp. 2318-2326 ◽  
Author(s):  
P. I. Abell ◽  
J. McClory ◽  
H. E. Hendry ◽  
K. L. Wheatley
Keyword(s):  
Oxygen Isotope ◽  
Isotope Ratios ◽  
Drill Hole ◽  
Carbon And Oxygen Isotopes ◽  
Oxygen Isotope Ratios ◽  
Nearshore Environments ◽  
Carbon And Oxygen Isotope ◽  
Isotopic Analyses ◽  
Northern Saskatchewan ◽  
Lowermost Part

Petrographic and stable isotopic analyses of stromatolitic sediments deposited in nearshore environments provides us with some of the best information available on ancient environments. Diamond drill hole CAR 58 penetrated 110 m of sediments in the lowermost part of the Proterozoic (probably Helikian age) Carswell Formation of northern Saskatchewan and gave us such an opportunity. The rocks are mainly dolostone and include, in descending order of abundance, cyanobacterial laminites, stromatolites, dolomicrites, dolorudites, breccias, and oolites. Stromatolites and Cyanobacterial laminites increase in abundance up-section, and deposition is interpreted as having taken place in conditions of increasingly restricted water circulation through time. The carbon isotope ratios vary from about −0.5 to −1.5‰ (Pee Dee Belemnite (PDB)) in the section except near the base where they assume values near −2.5‰. The oxygen isotope ratios (vs. PDB) increase from about −9.3‰ at the base to −7‰ at the top, with anomolously high values, more positive than −7‰, at two positions in the sequence. Original depositional structures and textures are still visible in most of the rocks, but gypsum has been replaced by dolomite, there has been some silicification, and original features have been obliterated by dolomite rhombs in a few samples. The upward trend to less-negative values of the oxygen isotope ratios is interpreted in terms of changing depositional environment involving a deepening but more protected basin, with increased evaporational concentration of the heavier isotope. Scatter diagrams of carbon and oxygen isotope ratios place the Carswell Formation dolomites close to the mainstream of other Proterozoic stromatolites but indicating some evaporative alterations during deposition.

The Hermes oil field: a small field takes wings

2009 ◽  
Vol 49 (1) ◽  
pp. 221 ◽  
Author(s):  
Greg C Smith ◽  
Jai Louis ◽  
Roy White ◽  
Ritu Gupta ◽  
Roger Collinson
Keyword(s):  
Scenario Analysis ◽  
Flow Line ◽  
Field Potential ◽  
Statistical Design ◽  
High Water ◽  
Oil Field ◽  
Oil Accumulation ◽  
Field Development ◽  
Uncertain Variables ◽  
Water Cut

The Lambert field was discovered in 1973 with oil reservoired in Tithonian turbidites. It was viewed as uneconomic until 1996 when re-evaluation led to discovery of the adjacent Hermes oil accumulation by Lambert–2. The Lambert–3 producer was drilled nearby to Lambert–2 in 1997 and tied back to the Cossack-Pioneer floating production storage offloader (FPSO). Lambert–3 was expected to drain about 25 MMBBLs of oil, coming off plateau after one year and declining substantially thereafter; however, it had produced more than 52 MMBBLs of oil by late 2008 without any water cut and may produce much more in the next 15–20 years. In contrast, several appraisal and production wells drilled since in the adjacent Lambert accumulation have only produced modest recoveries. Why were the original deterministic views of the Lambert-Hermes field so far from present estimates? This paper describes the approach taken to re-assess the Lambert and Hermes oil accumulations. First, the traps were reviewed by framing the main uncertain variables followed by a rigorous scenario analysis of the field. The work was expedited by using a statistical design to substantially reduce the number of scenarios required for modelling and simulation. The results included a statistical analysis and produced a better view of the probable reserves ranges. Remarkably, after 11 years’ production the field potential warranted re-appraisal. The scenario analysis indicated which uncertain variables needed attention and helped to select well locations. The results of appraisal should decide between several re-development options. The main possibilities for new field development include: drilling of additional oil producers; water shut-off in some producers; an additional flow-line to de-bottleneck oil production from Lambert and Hermes; re-instatement of a gas-injection line for gas-lift of wells at high water-cut; and installation of a new manifold further north in the Hermes accumulation to optimise field recovery.

Design and Execution of the First Large-Scale Polymer Injection Pilot in Sirikit Oil Field

2021 ◽  
Author(s):  
Weeraya Wuttipittayamongkol ◽  
Pannapon Trinavarat ◽  
Warisa Nuntaprayoon ◽  
Monrawee Pancharoen ◽  
Rapheephan Laochamroonvorapongse
Keyword(s):  
Large Scale ◽  
Oil Field ◽  
Production Performance ◽  
Water Flooding ◽  
Small Scale ◽  
Mechanical Degradation ◽  
Close Monitoring ◽  
Polymer Injection ◽  
Fluid Saturation ◽  
Water Cut

Abstract Becoming more mature with field-wide water flooding implementation for more than 30 years, Sirikit Oil Field (S1) is going forward to the next rejuvenating step of enhanced oil recovery (EOR). Generally, the field contains light oil (40° API) in highly stratified sand-shale sequences with low net-to-gross ratios. High reservoir temperature, low permeability, and high water cut observed from production make it even more challenging for polymer injection projects. Nonetheless, the success from a small-scale field trial has shown a promising future of EOR application in the field and brought an execution of the first large-scale polymer injection pilot. Polymer screening laboratory tests, a reservoir simulation study, data acquisition program and techniques, injectivity tests, polymer injection unit design, and risk assessment were parts of the pilot preparation, in which the key learnings from the previous pilot have been incorporated. The gathering and determination of baseline parameters including production performance, injection profiles, reservoir fluid saturation profiles, etc., were registered for ultimate evaluation. Then, the continuous polymer injection has been started since October 2019 in two separated fault blocks where 12 injectors and 20 producers are located in different injection patterns. During several months of polymer injection, both foreseen and unforeseen changes have enlivened the pilot management. Although the injectivity test with polymer solution prior to the pilot demonstrated no injection difficulty, several wells have shown injectivity deterioration with time. Mechanical degradation is induced in these wells by the installation of flow restriction devices to lessen solution viscosity and, hence, prolong polymer injectivity. Well integrity issues and artificial lift breakdown negatively affect field production and close-in wells make it harder for voidage replacement control. Immediate troubleshooting and close monitoring have been placed and eventually leads to the recognition of encouraging results. Polymer helps improve vertical injection profiles as seen from injection logging. Saturation logging presents a sign of oil saturation decrease around the wellbore area. Reduction of water cut and rise of oil production have pleasantly come after a few months from the start. Intensive surveillance program will be continued over the course of pilot injection. The critical success of the EOR pilot execution depends on the detailed planning, prudent surveillance and comprehensive evaluation. Sirikit oil field is moving to a turning point and the pilot outcome would lead the way to a further milestone, so as to avoid premature end of the field's production.

TRIALS OF A MULTIPHASE FLOW METER ON PRODUCTION PIPELINES FROM OIL WELLS

1994 ◽  
Vol 34 (1) ◽  
pp. 101
Author(s):  
G.J. Roach ◽  
J.S. Watt ◽  
H.W. Zastawny ◽  
P.E. Hartley ◽  
W.K. Ellis
Keyword(s):  
Multiphase Flow ◽  
Gamma Ray ◽  
Least Squares Regression ◽  
Mean Flow ◽  
Flow Meter ◽  
Horizontal Section ◽  
Oil Processing ◽  
Production Platform ◽  
Oil Water ◽  
Water Cut

This paper describes trials of a new multiphase flow meter (MFM) on the Vicksburg offshore production platform and at the oil processing facilities on Thevenard Island. The flow meter is based on two specialised gamma-ray transmission gauges mounted on a pipe carrying the full flow of oil, water and gas.Two MFMs were used in both trials, one mounted on a vertical (up flow), and the other on a horizontal, section of a pipeline linking the test manifold to the test separator. Measurements were made on flows of oil/water/gas mixtures from each well, and on combined flows of different pairs of wells.The r.m.s. difference between the flow rates determined by the MFM and by the separator output meter was determined by least squares regression. For the Vicksburg trial, the ratio of r.m.s. difference and mean flow rate was 8.9 per cent for oil, 5.6 per cent for water, 5.2 per cent for liquids, and 8.2 per cent for gas for flows in the vertical pipeline and slightly larger for flows in the horizontal pipeline. For the Thevenard Island trial, the preliminary results for flows in the vertical pipeline show the ratio to be 6.8 per cent for oil, 6.0 per cent for water, 3.4 per cent for liquids, and 5.9 per cent for water cut.

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