The Gravel Packing Chacteristics of Ethiope River Sediments, Southern Nigeria

Submitted: Jul 12, 2013; Accepted: Aug 26, 2013; Published: Aug 29, 2013 Abstract: Sand production in water, oil and gas wells is usually controlled by gravel packing techniques worldwide. Consideration in the gravel pack design requires that the particle size is five or six times the formation sand depending on the formation sand median diameter. Sieve analysis result shows that the grain sizes of sand and gravel of the Ethiope River sediments fall within the size range (0.378-12.0mm) recommended for a gravel pack by the American Petroleum Institute. Acid solubility test on the gravel and sand gives desirable results as the maximum solubility of 1.0% required for gavel pack is not exceeded. The sphericity and roundness of the particle grains range from 0.70-0.68 and 0.70-0.67 respectively, which is within the range ( 0.6) allowed for gravel pack. The presence of the objectionably high content of silt and clay in some of the samples particularly those collected near the Ethiope River source area (e.g. UM1-UM10) however reduces the pack efficiency and formation permeability as the “fines and mud” tend to clog the screen slots (openings). A possible solution to this problem will entail some systematic process of flushing out “fines and mud” from the deposit prior usage.