Dynamic Reservoir Well Interaction

Abstract

Dynamic Reservoir Well Interaction W.L. Sturm; W.L. Sturm TNO TPD, Delft, The Netherlands Search for other works by this author on: This Site Google Scholar S.P.C. Belfroid; S.P.C. Belfroid TNO TPD, Delft, The Netherlands Search for other works by this author on: This Site Google Scholar O. van Wolfswinkel; O. van Wolfswinkel TNO TPD, Delft, The Netherlands Search for other works by this author on: This Site Google Scholar M.C.A.M. Peters; M.C.A.M. Peters TNO TPD, Delft, The Netherlands Search for other works by this author on: This Site Google Scholar F.J.P.C.M.G. Verhelst F.J.P.C.M.G. Verhelst TNO TPD, Delft, The Netherlands Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Annual Technical Conference and Exhibition, Houston, Texas, September 2004. Paper Number: SPE-90108-MS https://doi.org/10.2118/90108-MS Published: September 26 2004 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Sturm, W.L., Belfroid, S.P.C., van Wolfswinkel, O., Peters, M.C.A.M., and F.J.P.C.M.G. Verhelst. "Dynamic Reservoir Well Interaction." Paper presented at the SPE Annual Technical Conference and Exhibition, Houston, Texas, September 2004. doi: https://doi.org/10.2118/90108-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Annual Technical Conference and Exhibition Search Advanced Search AbstractIn order to develop smart well control systems for unstable oil wells, realistic modeling of the dynamics of the well is essential. Most dynamic well models use a semi-steady state inflow model to describe the inflow of oil and gas from the reservoir. On the other hand, reservoir models use steady state lift curves for modeling of the wells. When producing oil from thin oil rims, this description does not sufficiently describe the well behavior observed in practice. For this reason, a model was built that describes both the dynamic flow of oil and gas towards the well bore and the dynamic flow inside the well. The integrated model provides a realistic description of the well dynamics on a time scale of minutes, which is the time scale that is required for development of a control system. As a result, the integrated model allows the development of model based gas coning control or water coning control schemes, as well as model based interpretation of well data.IntroductionOil producing wells often encounter instabilities during production. Various types of automatic control systems can be developed in order to prevent unstable operation. Due to the increasing availability of sensors and actuators applications of smart well control become gradually more feasible1,2,3. For the development of smart well control systems realistic modelling of the dynamic well behaviour is essential. From practical experience it appears that in several applications the interaction between the reservoir and the well plays a dominant role in the dynamic behaviour of the well. In order to still be able to develop control systems for these situations, the near well bore reservoir was modelled and was integrated with the well model, resulting in a model describing the dynamic interaction between reservoir and well.One condition for unstable oil production occurs at low gas lift rates and is known as heading. Although steady-state flow analysis sometimes indicates most efficient production at these gas lift rate, dynamic analysis predicts cyclic variations of liquid and gas production. This often results in periods with reduced or even no liquid production, followed by large peaks of liquid and gas.Another situation where unstable production occurs, is when oil is produced from a thin oil rim, where the gas cap is close to the perforations of the well. When increasing the drawdown a cone of gas will be formed. Due the formation of a gas cone, not only oil enters the tubing, but also gas will enter the tubing. In some conditions this can lead to excessive production of gas, and as a result a decreased or unstable oil production. In other conditions however a small amount of cone gas entering the well can create natural gas lift, and will stimulate oil production rather then disturbing it. For operation of an oil well where the risk of gas coning is present, it is important to know the conditions that affect the production of cone gas. Cone formation and production of cone gas is a dynamic phenomenon, involving both reservoir and well dynamics. When the well perforations are close to the water layer, also water coning can take place. Also water coning is a dynamic phenomenon, involving reservoir and well dynamics.A simulation model was developed with the aim to describe the main dynamic phenomena that are important for the development of smart well control systems. This includes the situations mentioned above. The model focusses on the dynamic interaction between the different subsystems, which allows some simplifications in the description of the individual subsystems.The structure of the model is explained in this paper and typical behaviour indicating reservoir well interaction is pointed out. The simulation results are compared to the results where only the dynamics of the well are described and where the reservoir dynamics are neglected. In addition the model was validated with field data from a thin oil rim reservoir. Finally different applications are mentioned how the model can be used for the optimisation of oil production. Keywords: reservoir model, gas lift, period time, artificial lift system, gas injection, dynamic phenomenon, production monitoring, cone gas, drillstem testing, spe 90108 Subjects: Artificial Lift Systems, Well & Reservoir Surveillance and Monitoring, Formation Evaluation & Management, Gas lift, Drillstem/well testing This content is only available via PDF. 2004. Society of Petroleum Engineers You can access this article if you purchase or spend a download.