The shaped charge was a development for armour piercing shells in the Second World War. It creates a very high pressure, but a highly focussed jet that is designed to penetrate the casing pipe, the cement and, as far as possible, into the formation. The components of the shaped charge used in oil well perforating, …
After successfully perforating using wireline guns, experts proposed that they could run similar guns on pipes. This allowed for longer sections of the gun to be utilized, reducing the rig time required for well completion. Further time savings could be achieved by combining the guns with the completion string. In the 1930s, Halliburton patented the …
We use several methods to create a hole from the wellbore through the casing and any cement sheath into the producing zone, such as shaped perforating charges, bullet guns, and abrasive jets. These methods are called perforating methods. Perforations create conduits into the reservoir that allow hydrocarbon recovery and influence it. Different perforating requirements are …
This is the more widely employed and reliable method. The design of SCSSV – surface control subsurface safety valve is typically aiming to operate independently of well conditions. This is because the downhole valve relies on hydraulic pressure. The pressure is supplied by a small 1/4″ monel control line strapped to the tubing to keep …
A tubing-retrievable subsurface safety valve (TRSCSSSV) is run as an integral part of the completion string. The equipment requirements for the oil and gas TRSV system are: the TRSV assembly, hydraulic control line and fittings, and a hydraulic control manifold. Like the wireline retrievable safety valve WRSV, the control line is attached between the TRSV …
After installation of the completion string, we can run, locate & lock a wireline retrievable subsurface safety valve WRSV into a safety valve landing nipple (SVLN) before production. The SVLN (valve nipple) is integral to the tubing string. The valves typically open due to the hydraulic pressure acting on a piston which moves a flow …
A subsurface safety valve (SSSV) is a downhole safety device installed in a well that can be closed in emergencies. An emergency may arise on or around a well from equipment failure, human error, collision with an offshore facility by a third-party vessel, fire, leaks, or sabotage. Why Do We Need Subsurface Safety Valves? The …
There are two basic types of well completions techniques: There is also another classification for well completion depending on the well Production Mode. This classification shall include the following: Open Hole Well Completion Type The open hole completion has the production casing set above the target intervals. We complete such a well with the producing …
A multiple completion is one where we can produce several different reservoir zones through separate flow paths within the same wellbore. As we shall see, we may accomplish this with tubing/annulus flow, multiple tubing strings, or by cementing several independent tubing strings in the same wellbore (a multiple tubingless completion). Reasons For Multiple Completions A …
Flowing wells equipped with a single tubing string are usually completed with a packer. Single-zone completions may involve the downhole commingling of production from several intervals within that zone. Examples of single-zone completions are shown in Figure 1. At the design stage, optimum tubing size for maximum long-term flow rate, future artificial lift needs, and …