Empirical Evidence Demonstrating Injection Containment and Absence of Injection-Induced Fracturing, Wilmington Oil Field Case Study
| Autor: | Ryan P. Kellogg, David J. Mercier |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Fuel Technology
Containment Petroleum engineering 0202 electrical engineering electronic engineering information engineering Energy Engineering and Power Technology 020207 software engineering Geology 02 engineering and technology Oil field 010502 geochemistry & geophysics 01 natural sciences 0105 earth and related environmental sciences |
| Zdroj: | SPE Reservoir Evaluation & Engineering. 23:1045-1059 |
| ISSN: | 1930-0212 1094-6470 |
| DOI: | 10.2118/195282-pa |
| Popis: | Summary Waterfloods in California operate under the US Environmental Protection Agency's Class II underground injection control regulations, which are tasked with the protection of underground sources of drinking water (USDW) within the state. A key aspect of this regulatory framework is the operation of water injection wells under a maximum allowable surface pressure (MASP) to ensure that injected water does not induce and/or extend formation fractures that could create a potential conduit connecting the hydrocarbon zone with identified USDWs. Determination of the MASP for individual injection wells has typically been calculated using a step rate test (SRT), but this method has been shown to be inappropriate for multilayered, unconsolidated sandstone reservoirs (Ershaghi and Ershaghi 2018), which are prevalent in Wilmington Field. To avoid the potential for misinterpretation of SRTs to imply fracturing in this context, in this paper we summarize the evidence demonstrating both the effective geologic containment of injected fluid in the hydrocarbon-bearing zones and the absence of injection-induced fracturing. In addition, a series of field tests were conducted to assess the stress sensitivity of the Wilmington reservoirs and investigate in-situ changes in the reservoir at higher injection pressures by combining multirate injection tests with injection profile surveys. These results provide data supporting the noted challenges associated with MASP determination for multilayered, unconsolidated reservoirs. In this paper, we give operators and regulators working in these types of fields a framework for assessing both injection containment and injection-induced fracturing that account for the unique properties of these formations. |
| Databáze: | OpenAIRE |
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