Wireline fluid sampling
- SPE, Richardson, TX (United States)
Accurate PVT data are crucial to well completion and production, formation evaluation and reservoir characterization. This is especially true for initial reservoir characterization where the PVF sample needs to be obtained prior to production. It is essential that the fluid sample be recovered as closely as possible to in-situ conditions whether by drill stem or wireline formation for. The need to remove drilling mud filtrate prior to collecting a sample has been widely recognized. Wireline testers which can pump fluid from a formation until filtrate is reduced to a minimum overcome this problem. While reducing sample contamination has been addressed, little emphasis has been placed on the need to control inlet pressure during filtrate removal or during sampling. Reducing contamination is important; however, there is equal need to determine the critical sampling pressure. The purpose is to prevent phase separation in the formation by regulating the sampling process based on this information and thereby obtain a more representative reservoir fluid sample. A recently introduced wireline instrument provides the capability of measuring the critical pressure prior to sampling, of controlling the sample pressure and of increasing the pressure in the sample container to compensate for temperature decline during delivery of that sample to a testing laboratory. Example of pressure tests while pumping and during pressure buildup are presented along with indicated sample properties. Introduction Wireline Formation Testers (WFT) provide an cost effective means to determine pressure as a function of depth and to recover samples of fluid from formations at selected depths. No other method can provide this type of information. Pressure data are used to estimate mobility, fluid contact and fluid density.
- OSTI ID:
- 207314
- Report Number(s):
- CONF-951002--
- Country of Publication:
- United States
- Language:
- English
Similar Records
Wireline sealing apparatus and method for use with a drill string
In-situ determination of capillary pressure, pore throat size and distribution, and permeability from wireline data