Aquatic environments are extremely difficult for developing, deploying, and maintaining wireless sensor networks. Networks deployed in aquatic settings face multiple challenges, such as marine fowling of equipment, limited power supply, communications difficulties, and restricted accessibility for maintaining and updating sensor nodes. The SEMAT project is an initiative to create "smart", low-cost, heterogeneous wireless sensor networks, tailored to alleviating the aforementioned constraints. Networks can be instantly deployable with minimal setup overheads and can utilise equipment from multiple vendors. This paper presents our experiences with developing the initial technologies to establish SEMAT for field tests. We present the design methodology and challenges faced for creating a marinebased heterogeneous wireless sensor network platform. The result is a low cost solution, with sufficient accuracy for undertaking a study into the factors contributing to Lyngbya algae blooms in Deception Bay, Queensland. The platform builds a case for the merits of the final SEMAT system, as ultimately many of the software and basic hardware challenges for future aquatic deployments have been overcome. This is significant as it allows researchers to focus on the area under study, rather than the specifics of setting up and managing the network.

EQT Production has implemented a new technique for drilling horizontal wells in the hard formations of the Appalachian Basin.Air percussion drilling has been adopted for use horizontally in the Berea sandstone, a hard and abrasive sandstone reservoir that had been traditionally drilled with roller cone bits. The evolution of the technology started with a packed-hole assembly that was trialed on three wells using stabilizer placement to provide directional control in the horizontal. The results were promising as penetration rates increased, but many trips were required to keep the wellbore in the desired target zone. To improve directional control, a percussion BHA with a bent housing positive displacement motor (PDM) was implemented. The introduction of the positive displacement motor with the air hammer produced the same penetration rates seen in the packed-hole assembly while providing the directional control needed. Since mid 2009, the PDM percussion assembly has become the standard practice for drilling Berea horizontal wells, replacing the roller cone BHA. Through June 2010, over 40 wells have been drilled using the assembly. The lateral portion for a majority of the wells is now drilled in one run, reducing total drilling time from 22 to 13 days, dry hole costs by over one half and total well costs by about one third.

Developing a large sensor-based observation system faces two serious challenges: 1) incompatible sensor technologies from different manufacturers; and 2) complexity of the data streaming process. Sensor Abstraction Layer (SAL) is a middleware integration platform which enables a single interface to view and control heterogeneous sensors regardless of the technologies involved. Although SAL addresses the software compatibility issue of sensors from different manufacturers, it provides limited support for real-time visualisation of the sensed data. Real-time data streaming is extremely useful for scientific modelling and presenting study results for which the sensor network has been designed to investigate. This limitation of SAL can be improved through using existing purpose-built technologies such as the Ring Buffer Network Bus Data Turbine. The Data Turbine is an open-source data management system which provides services for data stream management, routing, monitoring and visualisation. This paper introduces SAL-T (Transmission) which integrates SAL with the Data Turbine. SAL-T is an extra software layer that facilitates the management of the sensed data from SAL into the Data Turbine. Performance tests have been conducted using SAL-T in a simulated data streaming environment indicative of a wireless sensor network. The tests showed that SAL-T dramatically reduced network traffic and improved transmission times.

The majority of wireless sensor networks are built on bespoke platforms, that is, custom designed and built hardware with a light weight software stack. There are a number of advantages to this approach. First, the ability to closely match and minimise the resource requirements (e.g., power consumption and communications protocols) to those that are suitable for the intended deployment. Second, as an entire hardware and software stack is often designed or at least optimised for each deployment, the latest advances can be quickly incorporated. However, this model generally requires the expertise of hardware and software engineers to design and build the system. In turn, this increases the cost and tends to shift the focus away from the initial science towards the development of the wireless sensor networks. This paper explores the utility and practicality of building wireless sensor networks based on commercially available embedded single board computing platforms using standard consumer operating systems. Our test bed was built using Gumstix computing platform, running a Linux Operating System (OS) with a java-based middleware coupled to low-cost scientific grade sensors. Test deployments have found this to be a highly versatile solution, able to leverage the flexibility of commodity hardware and software while maintaining reasonable utility.