Petroleum Engineering

WELL COMPLETION

Well completion is the process of making a well ready for production (or injection) after drilling operations. This principally involves preparing the bottom of the hole to the required specifications, running in the production tubing and it’s associated down hole tools as well as perforating and stimulating as required. Sometimes, the process of running in and cementing the casing is also included. After a well has been drilled, should the drilling fluids be removed, the well would eventually close in upon itself. Casing ensures that this will not happen while also protecting the wellstream from outside incumbents, like water or sand.

WELL PRODUCTION

A “production Engineering” refers to the Engineering that extract oil or gas from subsurface well deposits. Production wells are drilled thousands of feet into the earth directly into oil or gas rich deposits contained in underground formations. Traditionally, vertical wells were utilized to extract oil or gas from one subsurface reservoir. Horizontal drilling was later developed in order to extract oil and gas from multiple reservoirs through the use of one well, which is horizontally angled into the deposit.

ARTIFICIAL LIFT

Artificial lift refers to the use of artificial means to increase the flow of liquids, such as crude oil or water, from a production well. Generally this is achieved by the use of a mechanical device inside the well or by decreasing the weight of the hydrostatic column by injecting gas into the liquid some distance down the well. A newer method called Continuous Belt Transportation uses an oil absorbing belt to extract from marginal and idle wells. Artificial lift is needed in wells when there is insufficient pressure in the reservoir to lift the produced fluids to the surface, but often used in naturally flowing wells to increase the flow rate above what would flow naturally. The produced fluid can be oil, water or a mix of oil and water, typically mixed with some amount of gas.

WELL TEST

Well and formation tests, which entail taking measurements while flowing fluids from the reservoir, are conducted at all stages in the life of oil and gas fields, from exploration through development, production and injection. Operators perform these tests to determine whether a formation will produce, or continue to produce, hydrocarbons at a rate that gives a reasonable return on further investments. Operators also use test data to determine the limits of the reservoir and to plan the most efficient methods for producing wells and fields. During testing, operators measure formation pressure, characterize the formation fluids and reservoir and determine permeability and skin—damage to the formation incurred during drilling or other well operations. Data that indicate how the formation reacts to pressure increases and decreases during a test can also reveal critical information about the reservoir.

WELL CONTROL

The technology focused on maintaining pressure on open formations (that is, exposed to the wellbore) to prevent or direct the flow of formation fluids into the wellbore. This technology encompasses the estimation of formation fluid pressures, the strength of the subsurface formations and the use of casing and mud density to offset those pressures in a predictable fashion. Also included are operational procedures to safely stop a well from flowing should an influx of formation fluid occur. To conduct well-control procedures, large valves are installed at the top of the well to enable wellsite personnel to close the well if necessary.

WELL STIMULATION

Well stimulation is a well intervention performed on an oil or gas well to increase production by improving the flow of hydrocarbons from the reservoir into the well bore. As a well stimulation technique, hydraulic fracturing has a wide range of applications, including the development of unconventional resources, production enhancement in low- and moderate-permeability reservoirs, bypassing near wellbore damage in high-permeability reservoirs, reducing sand production in loosely consolidated or unconsolidated sandstone reservoirs, and connecting the natural fractures in a formation to the wellbore.