Petrophysics free essay sample

Conceptual The South Tapti gas field, situated in the Arabian Sea off the western shoreline of India, has been on creation throughout the previous three years. Drill Stem Tests (DST) led in five zones in the main examination very much demonstrated high sand creation in all the tests at drawdowns as low as 20 psi. Because of the unconsolidated idea of the supply sand, it was chosen to rock pack every single future well. At first, the High Rate Water Pack (HRWP) strategy was utilized on 13 fruitions including some stack and particular consummations. Because of an adjustment in the boring liquid to an oil based mud (OBM) framework and the higher harm related with the it, it was later chosen to switch the rock pressing procedure to ‘Frac and Pack’. This included production of a little frac to sidestep the close wellbore harm utilizing a gel-based liquid, trailed by rock arrangement utilizing the HRWP. The Frac Pack procedure was taken a stab at 10 culminations. Broad creation and weight information gathered on the above fruitions show that the ‘Frac Pack’ method has prompted a decline in the mechanical skin by very nearly 70 %. All the more critically, it has likewise been liable for diminishing the Rate Dependent Skin Coefficient, D, by 50 %, which greaterly affects the well efficiency since these wells are created at normal paces of 25 MMSCFD. This paper portrays the rock pressing procedures utilized in the South Tapti gas field, their advancement and the outcomes accomplished. Inroduction The South Tapti field, situated off the Western shore of India, is spoken to by a progression of rotating sand and shale successions. The upper repository interims are overwhelmed by tidal-bar and direct sands stored in a deltaic domain while the lower sands speak to chiseled valley stores comprising generally of alluvial/fluvial channels, tidal bars and tidal rivers. The exploratory wells penetrated in the field showed solid sand creation propensities because of the unconsolidated idea of the repository rock. This was verified by broad testing of the principal improvement well when all the five zones tried created sand significantly under amazingly low tension drawdown conditions. The consummation arrangement for the field concentrated on forestalling sand entrance while limiting the close to all around bore harm innate in any sand control application. The early advancement wells were rock pressed utilizing the high rate water pack (HRWP) method. These underlying fruitions were profoundly effective in forestalling sand creation yet in addition incited noteworthy harm all the while. The issue was complemented when the penetrating mud framework was changed to an oil base framework trying to counterbalance repetitive boring issues emerging out of unconsolidated sandstone and nearness of responsive dirts. This required an adjustment in consummation theory so as to guarantee that the wells hold high efficiency with powerful sand control. Geologic and Reservoir Characterization The South Tapti field is restricted by an expansive SW-NE inclining, doubly plunging anticline. The field has up to 13 distinctive Oligo-Miocene gas bearing sands, isolated by shales. The store sands were kept in both etched valley and deltaic settings. Repository sands inside etched valleys comprise of alluvial/fluvial channels, tide-affected channels and tidal bars. The channel sands normally are the cleaner sands with great porosity penetrability and up to 20 m thick, while the tide-impacted channels and tidal bars are shalier, with progressively humble porosity and porousness. Dirt MINERALS 1. Unique: Tapti Basin in Surat Depression, Bombay Offshore is described by totally siliciclastic progression. The centers and cutting examples, and wireline logs give significant data about the stratigraphy, bowl fill, mineralogy, source and supply rock attributes. Well under investigation is situated in South Tapti sub-bowl and contains gas-bearing sandstone inside Mahim Formation of Late Oligocene age. The cuttings and centers have been megascopically inspected and with the guide of electrical log information, the litholog of the well is readied. The investigation includes XRD and significant component examination of chose tests. The XRD and advanced log information from Natural Gamma Sepctrometry (NGS) log demonstrate that montmorillonite is the significant dirt mineral present in the upper piece of the progression, though kaolinite present in the lower section (1868 m MD to 2427 m MD). Kaolinite is clearly framed by beginning times of entombment diagenesis, while montmorillonite is an enduring result of the Deccan Basalt. Interpretative lithology from the well log reaction shows that supply sandstones include created inside the profundity interim of 1865m TVD to 1945 m TVD inside overwhelmingly shale lithology. Supply sandstones are semiconsolidated, medium to coarse grained and respectably all around arranged. Quartz is the predominant detrital part in all the sandstones. Pay sands are quartz arenite while non-pay sands are quartz wacke with shifting measure of dirt network. Kaolinite in the repository area decreases the penetrability of quartz wacke, yet upgrading porosity in microlevel. Carbonate, siderite and iron oxide are fundamental solidifying material. Significant component information indicating that clastic residue were conveyed to the bowl potentially by the Proto Tapti waterway yet they might be having double wellspring of birthplace. The discriminant elements of Meyer and Nederlof, 1984 has demonstrated that the examined arrangements don't have source rock potential. Watchwords: Tapti Basin, Bombay Offshore, hydrocarbons, provenance and mud minerals. quartz wacke, yet improving porosity in microlevel. Carbonate, siderite and iron oxide are primary establishing material. Significant component information indicating that clastic dregs were conveyed to the bowl potentially by the Proto Tapti waterway yet they might be having double wellspring of root. The discriminant elements of Meyer and Nederlof, 1984 has demonstrated that the contemplated arrangements don't have source rock potential.