Permanent Downhole Monitoring is a Keystone of Multi-Fractured Horizontal Wells Line Drive Flooding Management
Authors: Morozovskiy Nikita , Grishina Ekaterina , Rybakov Roman , Feoktistov Roman 
Published: October 2016

The current state of the resource base implies an increase in deposits of objects with low and ultra-low permeability. In order to cost-effective production of layers reveal horizontal wells (HW) with a multi-stage hydraulic fracturing (MSHF) and wells network sealed, and introduced more stringent in-line system design.

The rational development of formation in these conditions implies a complication develop control system that would cover the whole period of the wells.

This paper describes an example of the development and implementation of such a system, wich is based on the methods of permanent hydrodynamic monitoring with the involvement of a wide range of geological and oilfield information.

Development of the system began with the modernization of the methodology of interpretation of standard methods ofproduction data analysis (decline analysis). In particular, it was necessary to justify the algorithm for determining the number of working cracks fracturing - the main parameter affecting farm productivity with MSHF, and ambiguously defined directly on the results of well tests on traditional interpretation methods.

The algorithm is based on solution of the direct problem of pressure field distribution in the reservoir on the numerical and analytical models of multi-fractured horizontal wells (MFHW), taking into account the different distances between the cracks, permeability, well length and cracks. Modeling was verified field experiments materials: hydrodynamic, geophysical and microseismic.

The results of simulation on the model allowed us to develop an improved methodology for well tests interpretation. The basis of the method laid down in the actual fact of the formation of geological and technological conditions of the studied field pseudoradial two flow regimes, the first of which is associated with the influx of individual fractures, and the second with the influx of the entire trunk entirely. The ratio of seeming flow capacities, determined based on these modes, equals to the number of active fractures.

The advantage of this method is, inter alia, the possibility in some cases, to abandon costly specialized studies (microseismic, special PLT), restricting only the interpretation of the results of well tests and use the additional field information (fracking fluid efficiency, proppant tonnage, etc.).

The use of hydrodynamic monitoring permits to efficiently monitor field development during the entire life cycle of a horizontal well with multistage hydraulic fracturing: using advanced techniques of well test interpretation to justify start parameters according to the filtration properties and the energy state of the reservoir, the number of worcing fractures, scin, etc.;on the basis of the data of the filtering model to control the power state and quality of the connectivity throughout the life of the well;monitoring og wells interferation and effectively manage the reservoir pressure maintenance system;Forecast further operation of individual wells and well clusters on the field.

The proposed algorithms have allowed describing in detail the operation of 40+ wells at one of the fields in Volga-Urals region, without additional testing, i.e. without production loss and extra expenditures.

The novelty of the work is to establish an improved model of well test interpretation based numerical simulation and a representative sample of the results of well test, in conjunction with the additional commercial information.

Implementation of the proposed control system has enabled more effective approach to the development of complex constructed object. This system allows little or no additional financial cost to implement measures to control mining.