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In recent years, more attention has been turning towards the tight reservoirs. Therefore, completion configurations with multi-stage hydraulic fracturing take a special place in available technology toolbox. The widely spread multistage hydrofracturing in sidetracks (with collar cementing) has the following technological flaws: a long well reconstruction cycle; restrictions related to placing annular packers; possible leakage of the cement collar; failure to reach the target depth with the liner due a multitude of elements involved. Moreover, the current way of work organization and the current state of technology makes it hard to achieve shorter sidetracking and hydrofrackturing cycles without changing the completion design. To solve these problems, a fundamentally new approach was introduced - to combine the advantages of continuous cementing and ball activated MSHF completion systems. One of the Russian companies has developed the equipment required. A number of stand tests were carried out after the manufacturing that confirmed the design feasibility. During the project implementation, a risk assessment exercise was performed for drilling and completion jobs, as well as for the multi-stage hydraulic fracturing, whereupon risk mitigation and exclusion measures were identified. As a result, the cementing program was significantly revised, considering the special nature of the work ahead. Based on the results of the project, wells with horizontal sidetracks and continuous cement completions for subsequent MSHF (not used before in the Company) were successfully reconstructed. Due to an integrated approach and close interaction of all stakeholders already at the early stage of equipment testing and prior to the project implementation, it was possible to successfully finalize the installation and cementing of the completion systems. Subsequently, the successful completion job ensured uninterrupted MSHF operations in the cemented liner. |
