Equipment

Requirements of the scientific drilling community are often different than those of the commercial sector. Scientific projects focus on sample quality, collection of fluids and gases, and emplacement of instrumentation and monitoring devices. This emphasis often requires specialized drilling equipment. DOSECC has several unique drilling systems that have been developed specifically for scientific requirements.

DOSECC Specialized Land Drilling Equipment

The figure below shows the hoisting capacities and the corresponding coring depth capacities for each of the DOSECC land drilling rigs.

DOSECC Hybrid Coring System (DHCS)

The DHCS is a significant advancement in the state of the art for deep continuous coring. It is tophead driven wireline coring system that attaches to a host rotary rig. It is used for continuous wireline coring; when the operation requires tripping pipe, opening hole, setting casing, or cementing, the system can be set aside and the capabilities of the rotary rig used. The most cost-effective drilling methods are used for each operation.

Modified CS-1500 Coring Rig

The DOSECC modified CS-1500 coring rig is designed for use in land-based as well as shallow water coring. Rig modifications include upgraded hoisting capabilities that allow coring up to 4000 feet using HQ.

Modified CS-500 Coring Rig

A man-portable rig, DOSECC's modified CS-500 coring rig can be used for either conventional wireline diamond coring or sample collection in shallow lake and marine environments. The system has a coring capability of up to 200 m using either P-size diamond coring or the DOSECC Lake System (DLS) suite of sampling tools. It can collect up to 300 m of HQ-size core.

DOSECC Specialized Water-based Drilling Equipment

For drilling on lakes and in the shallow marine environment, DOSECC has three separate drilling systems. In addition, DOSECC has a service boat and is acquiring a portable dynamic positioning system that can be used on vessels of opportunity. The following describes the drilling systems we have developed for lakes. As important as the platforms and drilling rigs, DOSECC has developed a set of sampling tools that have proven to be very successful in the collection of continuous core samples under a variety of conditions.

The figure below shows the various DOSECC’s Specialized Water-based Drilling Equipment and the depth capacity for each system.

GLAD800 (Global Lake Drilling to 800m) System &

GLAD200 (Global Lake Drilling to 200m) System

The GLAD800 and the GLAD200 were designed to collect long continuous core in lake sediments. Modern lakes preserve proxies that document regional climate history at high resolution, therefore, collection and analysis of lake sediment cores is critical for determining the global climate record.

Active Heave Compensated Rig (AHC800)

The DOSECC AHC800 is an active heave compensated (AHC) coring rig that is capable of retrieving continuous core to depths of 800 m (water + sediment) in shallow marine and deep lacustrine environments. The system is modular and designed to fit on a variety of drilling platforms. The AHC800 uses the same suite of proven sampling tools as does DOSECC's GLAD800.

DOSECC’s Six Specialized Drilling Tools

A variety of drilling tools is required to collect high-quality core in different types of sediments in recent lakes. DOSECC has developed six standard tools that we collectively named the DOSECC Lake Coring System (DLS). The tools are wireline deployable and are similar to those used in the Ocean Drilling Program (ODP) and commercial geotechnical work. In order of increasing sediment stiffness, these tools include:

Shelby Push Tube
Hydraulic Piston Core (HPC)
Extended Shoe, non-rotating
Extended Core Bit, rotating (nicknamed The Alien)
Diamond Core Bit (mining)
Non-sampling assembly

The DLS cores a hole 5.50 inches (139.7 mm) in diameter. Most of the tools were designed to collect core within an ODP plastic liner that has an inner diameter of 2.44 inches (62 mm). The exception to this is the Extended Core Bit that collects core of 2.40 inches (61 mm) in a plastic liner. Core runs are 3 meters in length.

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