The most common method for determination of drained gas reserves is a method based on the solution of material balance equation. In case of gas drive, this equation can be solved quite simple and clear. In case of water drive, the application of classic approaches on the basis of solution of material balance equation is quite complicated. Usually these approaches are not used. The alternative approach was suggested within the framework of this paper in order to develop an express method for determination of drained reserves at water drive. This approach allows to identify the amount of invaded water in the accumulation and to estimate drained gas reserves.

The paper reviews the performance evaluation of measures against condensate banks in bottomhole zone. The study is based on compositional simulation. According to the results, optimal parameters for LNG injection and dry gas displacement in the formation are selected; duration of the measures taken and incremental recovery are evaluated.

Specific of gas field development suggests a constant level of gas production in order to provide stable loading of gas field processing and transport facilities. At this point, when production of major development objects commences to fall, start of minor objects production is supposed to occur. Having united surface facility and separate reservoir simulation of segregated layers with joint well stock a question of accuracy in measurement of hydrocarbon production is arisen. In addition, at the entry of production of minor objects with distinctive reservoir pressure a problem of appropriate distribution of wellhead and downstream pressures can be revealed.In this paper mechanism of building of a multiple layer oil and gas condensate field integrated simulation model (ISM) is described. Construction of integrated model will allow resolving the problems outlined above. Besides, running of field development simulation cases with different order and tempo of production will be significantly simplified.Separate compositional models made for each development object have been selected for integration in the ISM. However, consolidation of these models is complicated by the issue of demanding a lot of resources for storage and computation time. Therefore, a transition from compositional to black oil models has been performed in order to obtain production data. Detailed gas composition required for integration with a gas processing system can be gained by a delamping procedure.As a result of building integrated simulation model a flexible tool of effective management of field development has been obtained that makes it possible to run simulations for both major and minor objects simultaneously and taking into account the field infrastructure (gathering and compressor facility); to assess the possibility of joint production of separate layers and consider the impact of gathering system on hydrocarbon production as well. When comparing the simulation time in different types of models, without significant loss of simulation quality, the average acceleration is about twenty times. This allows obtaining results much faster and further improving it.

A case study of a gas-condensate field located on the northeastern shelf of Sakhalin Island demonstrates the possibility of development of condensate-containing gas reserves by drilling very long ERD wells (drilling from the shore). The development system described in the paper includes drilling well with upward orientation. Such design provides complete cleaning of a wellbore from fluids and solids accumulated over a long period of maintenance-free operation. The choice of a development system using horizontal wells is also associated with the geological structure of the field (massive type accumulation with a single gas-bearing contour is broken by tectonic faults into separate blocks with different hypsometric elevations). Under the technical, economical (drilling from platform and from land, the use of subsea production systems, ice gouging with hummocks), and environmental (presence of valuable fish species in water areas and permanent residence of indigenous peoples) limitations, the development of individual wells with vertical completions turned out to be unprofitable. For the first time for this type of accumulation located in a coastal zone, a unique method of monitoring the recovery of reserves within the cross-section, as well as movement of the gas-water contact without the use of monitoring and pressure observation wells was suggested.

3D hydrodynamic modeling is the standard tool for predicting the development of hydrocarbon (HC) fields. The relevance of the work is associated with the need to introduce fast and affordable optimization algorithms into engineering practice, which will reduce the cost of computer time to justify the best and most effective development solutions. The authors have proposed a new express method for finding the optimal option for the development of deposits. The method works with discrete sets of possible variations of the required development parameters (for example, the number of wells, the type of completion, the rate of hydrocarbon reserves withdrawal etc.) and minimizes the number of launches of the reservoir simulation simulator per forecast required for the feasibility of various combinations study of parameters and finding both local and global optimal combinations. Compared with other methods, its advantage is simplicity and realizability in the “manual” mode with a small number of variable parameters, which can be useful for practical problems. The method uses the principle of iterations and is tested on several examples, including the results of hydrodynamic modeling, a comparison is made with known optimization algorithms — in some problems the method allows finding the optimum faster. For example, in the problem of finding the optimal location of horizontal wells, the iterative search turned out to be faster than the “swarm of particles” method. On the other hand, the method does not allow one to reliably determine the optima of complex objective functions that have several local optima. Testing was carried out on the Himmelblau and Rosenbrock functions: in the first case, all five local optima were found, in the second case, seven out of twelve.