- Home
- Conferences
- Conference Proceedings
- Conferences
IOR 1991 - 6th European Symposium on Improved Oil Recovery
- Conference date: 21 May 1991 - 23 May 1991
- Location: Stavanger, Norway
- ISBN: 978-94-6282-133-0
- Published: 21 May 1991
81 - 100 of 100 results
-
-
Nonequilibrium adsorption of surfactants onto reservoir cores from the North Sea. The effects of oil and clay minerals
Authors T. Austad, P. A. Bjørkum, T. A. Rolfsvag and K. B. ØysædNonequilibrium adsorption of ethoxylated surfactants, mixtures of sulfonates and nonionic alcohoIs, onto two North Sea reservoir sandstone eores has been studied at reservoir temperature. One of the cores was cleaned prior to the adsorption studies, and the other core contained residual oil saturation, thus maintaining the reservoir wettability. The adsorption was followed by circulating the surfaetant solution through the cores for several months (1700 PV), using synthetic sea water.
-
-
-
On the simultaneous determination of dispersion and nonlinear adsorption parameters from displacement tests by using numerical models and optimization tehcniques
Authors C. A. Grattoni and M. S. BidnerThe simultaneous determination of the dispersion and nonlinear adsorption (Freundlich or Langmuir) parameters is obtained automatically by matching results of numerical models with the breakthrough curve measured during a laboratory displacement test. This matching is performed by applying multivariate optimization techniques to minimize the differences between numerical and experimental results. Numerical solutions are obtained by solving the convection-dispersion-nonlinear adsorption equation by finite differences using the Crank-Nicolson method with iterations to account for nonlinearities.
-
-
-
Irreversible adsorption and dispersion effects in progagation of thin slugs of chemicals
Authors V. M. Entov, I. S. Ginzburg and E. V. TeodorovichThe dynamics of the concentration profile in a thin slug of a chemical propagating along reservoir is investigated theoretically. Combined effects of convection, diffusion and partially irreversible adsorption are accounted for. Exact self-similar solutions are derived which shows that irreversibility of adsorption results in more rapid decrease of concentration maximum in the slug. The possible technological implications are discussed briefly.
-
-
-
Overcoming lateral reservoir heterogenerities via horizontal wells
Authors H. P. Freyss and K. BurgesSedimentary rocks are heterogeneous due to the nature of the depositional process. In a producing oil or gas field, the depositional heterogeneity is aggravated by the unbalanced process of oil or gaswithdrawal through disparate producing vertical wells. Overall, this leads to large pressure and saturation imbalances in the various sections of a field and uneven drainage resulting in lower ultimate hydrocarbon recovery.
-
-
-
Control of inflow performance in a horizontal well
Authors R. Tailby, J. Alvestad and A. HenriquezA flexible and cost-effective control of the inflow performance of horizontal wells by the use of multiple completions inside prepacked screens or perforated liners is presented.
-
-
-
Modelling of pressure drop for threephase flow in horizontal wells
Authors V. Korady, G. Renard and P. LemonnierIn most usual situations, the flow into an horizontal weIl will be turbulent due to high flow rates and is expected to have a large impact on the weIl behaviour and production performance. Therefore, accurate pressure drop calculations are needed for a proper representation of mono and multi-phase flow in the wellbore. This is of great interest when simulating highly permeable oil rims when water or gas coning may occur.
-
-
-
Simulation of vertical oil displacement towards horizontal and multi-hole wells
Authors M. M. Maksimov, L. P. Rybitskaya, M. L. Surguchev and V. P. TabakovWhen different types of horizontal wells became involved in oil field development practice, a problem of numerical simulation of the development processes has arisen.
-
-
-
The important effect of pattern shape upon the performance of horizontal wells
Authors R. M. Butler and R. SuprunowiczDespite statements in the literature which are to the contrary, the productivity of horizontal wells increases, in most practical cases, at a rate which is more than proportional to their length.
-
-
-
Imrpoved oil recovery in the global energy perspective
By P. JacquardThe story of oil in the last 25 years has been a paradoxical one. Around 1970, oil reserves amounted to 550 billion barrels. But in the light of the regular decline in the number of years of reserves, some experts did not hesitate to predict that the age of oil would soon come to an end.
-
-
-
The North Sea petroleum history and experience - "An lOR viewpoint
By F. Al-KasimIt is indeed a pleasure and an honour to be invited to speak to you here today. Allow me therefore to extend my sincere thanks to the organizers of this symposium for availing me of this splendid opportunity.
-
-
-
Improved oil recovery with special emphasis on offshore conditions
Authors T. A. McCracken and P. J. BriggsThe remaining oil reserves in the UKCS and Norwegian North Sea are some 18¹ billion barrels. Figure 1 shows a plot of expected recovery factors from 40 UK and Norwegian North Sea fields. The recovery factors have been arranged in ascending order and plotted versus the cumulative percentage of the total initial oil in place from the 40 fields. It can be seen from Figure 1 that the median recovery factor is 42%. The original oil in place in the North Sea is probably in the range of 70 to 120 billion barrels. This gives a residual oil volume of 40 to 70 billion barrels. We conservatively assume that reserves growth of 5% of oil in place can be attributed to improved reservoir management techniques with a further 5% growth through the application of EOR. This amounts to an Improved Oil Recovery (lOR) target of between 7 and 12 billion barrels from the currently discovered North Sea oilfields. In addition we estimate that there remain some 15 billion barrels of oil yet to be discovered, lOR will also expand this resource. There is tremendous target resource for additional reserves to be generated though lOR technology.
-
-
-
Reservoir characterization
More Lessuncertainties about static (affecting volume) and dynamic (affecting flow) reservoir characteristics and future operational factors (affecting regularity) often combine to yield a significant composite technical uncertainty about a field's production forecast.
-
-
-
A Summary of R&D needs for gas injection processes
By F. J. FayersAs shown in the title slide, gas displacement has three broad areas of application to oil recovery, namely miscible, or "nearly miscible", processes, gravity drainage, and fractured reservoir systems. We have seen papers at th is Conference which come into each of these categories. The technology of gas displacement is becoming mature from some points of view, ahhough there are still many stimulating and difficult research challenges for the future. Gas displacement is now established as a successful and economic method for Improved Oil Recovery in light oil reservoirs, even with oil prices as low as say $18 per barrel. The controlling parameters are oil recovery efficiency, where 5 Mscf/bbl is not an unreasonable net target with gas recycling, and gas price, which needs to be in the range of $1-2 per Mscf. In terms of resource conservation, an advantage of gas displacement is that the injected gas is not all lost, but most of it can be produced later for another purpose.
-
-
-
Status of chemical flooding
By J. R. BraggGood afternoon. First, I would like to thank Odd Skontorp and all of the Organizing Committee for the opportunity to help summarize the status of chemical flooding and per'haps raise some topics for reflection and discussion.
-
-
-
From well data to a complete description of a reservoir using geostatistical methods
Authors R. Eschard, B. Doligez and G. LelochThe use of new coneepts in sedimentological interpretation (stratigraphic sequences, carefully done deseription of the cores...) combined with new tools in geostatistics (variograms, proportion curves...) allows to characterize the size and the frequency of sedimentary bodies and of their internal heterogeneities. The geological interpretations and constraints appear to be crucial prerequisites for the consistency of the method.
-
-
-
A Statistical procedure on analysis of acoustic logs for identifying microfractures in carbonate systems
By P. TerdichIn order to define the dynamical schemes of a reservoir it is necessary to reconstruct its main structural and lithological characteristics and, in carbonate systems, especially the distribution of fracturation pattern.
-
-
-
Commercial polymer injection in the Courtenay Field
Authors A. G. Putz and R. C. RivenqAn industrial oparation of polymer injection has been implemented in the Courtenay field which is a satellite of the Chateaurenard field. A large slug of partially hydrolysed polyacrylamide solution with a viscosity of 21 cPo is being injected to displace a 40 cPo oil.
-
-
-
Three-phase relative permeability model for arbitrary wettability systems
By K. O. TemengAn analytical model is proposed for computing three-phase relative permeability from twophase data. The new model is an extension of the well-known probability model due to Stone. with a normalized wettability index as an interpolating factor. Determination of three-phase residual fluid saturations is also discussed.
-
-
-
On the protection against coning provided by horizontal barriers of limited lateral extent
By S. EkrannThe paper determines critical rates to coning for horizontal and vertical wells shielded by favourably positioned impermeable horizontal barriers of limited lateral extent. Mathernatical techniques mimic those used by previous authors for unshielded coning. The Muskat approximation is employed. It turns out that vertical wells can benefit strongly from the presence of a barrier, as measured by the critical rate, depending on barrier position and radius. With horizontal weIls, however, the the critical rate to coning is decreased, except for very wide barriers.
-
-
-
Alternatives to the salinity gradient for controlling the effects of dispersion in surfactant floods
By J. W. BarkerNumerical simulation is used to review the effects of middle phase mobility on the efficiency of a threephase surfactant flood and the use of a salinity gradient to counter the adverse effects of dispersion (by producing 'self-sharpening' of the surfactent slug). Alternative means of producing self-sharpening behaviour are then investigated. Inclusion of an alcohol in the chemical slug is shown to be a viable alternative to a salinity gradient, provided that the phase behaviour properties of the alcohol are chosen correctly. However, under the assumptions that optimal salinity is independent of surfactant concentration and that surfactant partitions almost wholly into the middle phase when that phase exists, it is not possible to achieve self-sharpening behaviour merely by varying the formulation of the surfactant within the chemical slug.
-