Solutions and melts of stiff ('rod-like') macromolecules often exhibit nematic liquid crystalline phases characterized by orientational, but not positional, molecular order. Smectic phases, in which macromolecular rods are organized into layers roughly perpendicular to the direction of molecular orientation, are rare, owing at least in part to the polydisperse nature (distribution of chain lengths) of polymers prepared by conventional polymerization processes. Bacterial methods for polypeptide synthesis, in which artificial genes encoding the polymer are expressed in bacterial vectors, offer the opportunity to make macromolecules with very well defined chain lengths. Here we show that a monodisperse derivative of poly(gamma-benzyl alpha,L-glutamate) prepared in this way shows smectic ordering in solution and in films. This result suggests that methods for preparing monodisperse polymers might provide access to new smectic phases with layer spacings that are susceptible to precise control on the scale of tens of nanometres.

A continuous fl ow microwave system based on a transmission line short-circuited waveguide reactor concept is described. The continuous fl ow reactor is capable of operating in a genuine high-temperature/high-pressure process window (310 ° C/60 bar), applying a microwave transparent and chemical resistant cylindrical γ -Al 2 O 3 tube as reaction zone. The system can be operated in an extremely energy effi cient manner, utilizing 0.6 -6 kW microwave power (2.45 GHz). The application of the reactor for processing four chemical transformations in a high-temperature/high-pressure regime with a throughout of 3.5 -6.0 l/h is demonstrated.

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A low concentration chemical treatment has been developed for pumping into a producer from surface to stop water production without harming hydrocarbon production. Matrix reservoirs are the primary target, though the upper permeability limit is not yet known. Numerical simulation has shown that while such a treatment would not be universal, many viable targets exist. Horizontal wells and multilaterals can make ideal targets, as would many vertical wells in heterogeneous formations and hydraulically fractured wells. Key performance targets were set for these chemical selective water-blocking systems (often called relative permeability modifiers). A dilute, water-dispersed system was favoured as treatment volumes were expected to be large in some cases. Because some of the chemical will enter valued oil/gas zones, the chemical must collapse to allow oil/gas to flow back through treated rock. A mechanism for this is described. To be of wide use, the chemical system should inhibit water production in reservoir rock with matrix permeabilities up to 10 Darcy, and at temperatures up to at least 110°C. Simulation indicated the minimum degree of water block required for selected targets. However, laboratory tests showed that blocks beyond 99.5% could be slow to clean up to hydrocarbon flow under available drawdown. This gave a performance target range. Well targets should always have appropriate reservoir stratigraphy, but it may not be possible to log the wells pre-treatment to check hydrocarbon/water inflow distribution. Therefore some "high-risk" treatments would fail because of lack of separate oil inflow, or absence of any flow barriers (such as shale) between water and remaining oil. A simple remediation treatment option was therefore required. Also, low toxicity and compatibility with production facilities were seen as non-negotiable properties. We describe the key molecular design parameters derived to give a polymer/crosslinker system with the performance demanded from simulation. Laboratory test results showing the required water/oil block performance and long term stability (at 100 °C) are presented. Field deployment designs including "rule of thumb" treatment volumes are described. The polymer and crosslinker were manufactured at full scale for trial application. Quality assurance tests of this unique "dancing-thin- gel" system are detailed. Results of several full-scale "calibration" field trials are presented. Lab-field correlation appears to be acceptably robust. Introduction Drilling and completion technology has advanced to permit economic development of more challenging reservoirs. Use of multilaterals, extended reach, horizontals, sand-screen/gravel packs, barehole, or sub-sea completions has become common. When these non-conventional wells cut water, they often still have significant production potential. However, access for remedial work such as Water Shut Off (WSO) interventions is difficult and expensive. Further, use of established WSO technologies such as straddles or coiled-tubing (CT) squeezes requires a Production Logging Test to gain knowledge of the water inflow point. Even then there is still a significant risk of failure. A PLT may show where the water enters the well. But it says little about whether reservoir shales are effective barriers to induced crossflow after the water has been shut off. For bullhead WSO, a PLT is not needed to help placement, though it might still help to select lower risk targets.