Abstract: A method having the following steps: running a circulation valve comprising a reactive material into the well bore on the casing; reverse-circulating an activator material in the well bore until the activator material contacts the reactive material of the circulation valve; reconfiguring the circulation valve by contact of the activator material with the reactive material; and reverse-circulating a cement composition in the well bore until the reconfigured circulation valve decreases flow of the cement composition. A circulation valve for cementing casing in a well bore, the valve having: a valve housing connected to the casing and comprising a reactive material; a plurality of holes in the housing, wherein the plurality of holes allow fluid communication between an inner diameter of the housing and an exterior of the housing, wherein the reactive material is expandable to close the plurality of holes.

Abstract: A method having the following steps: running a circulation valve comprising a reactive material into the well bore on the casing; reverse-circulating an activator material in the well bore until the activator material contacts the reactive material of the circulation valve; reconfiguring the circulation valve by contact of the activator material with the reactive material; and reverse-circulating a cement composition in the well bore until the reconfigured circulation valve decreases flow of the cement composition. A circulation valve for cementing casing in a well bore, the valve having: a valve housing connected to the casing and comprising a reactive material; a plurality of holes in the housing, wherein the plurality of holes allow fluid communication between an inner diameter of the housing and an exterior of the housing, wherein the reactive material is expandable to close the plurality of holes.

Abstract: A method having the following steps: running a circulation valve comprising a reactive material into the well bore on the casing; reverse-circulating an activator material in the well bore until the activator material contacts the reactive material of the circulation valve; reconfiguring the circulation valve by contact of the activator material with the reactive material; and reverse-circulating a cement composition in the well bore until the reconfigured circulation valve decreases flow of the cement composition. A circulation valve for cementing casing in a well bore, the valve having: a valve housing connected to the casing and comprising a reactive material; a plurality of holes in the housing, wherein the plurality of holes allow fluid communication between an inner diameter of the housing and an exterior of the housing, wherein the reactive material is expandable to close the plurality of holes.

Abstract: A method having the following steps: running a circulation valve comprising a reactive material into the well bore on the casing; reverse-circulating an activator material in the well bore until the activator material contacts the reactive material of the circulation valve; reconfiguring the circulation valve by contact of the activator material with the reactive material; and reverse-circulating a cement composition in the well bore until the reconfigured circulation valve decreases flow of the cement composition. A circulation valve for cementing casing in a well bore, the valve having: a valve housing connected to the casing and comprising a reactive material; a plurality of holes in the housing, wherein the plurality of holes allow fluid communication between an inner diameter of the housing and an exterior of the housing, wherein the reactive material is expandable to close the plurality of holes.

Abstract: A method having the following steps: running a circulation valve comprising a reactive material into the well bore on the casing; reverse-circulating an activator material in the well bore until the activator material contacts the reactive material of the circulation valve; reconfiguring the circulation valve by contact of the activator material with the reactive material; and reverse-circulating a cement composition in the well bore until the reconfigured circulation valve decreases flow of the cement composition. A circulation valve for cementing casing in a well bore, the valve having: a valve housing connected to the casing and comprising a reactive material; a plurality of holes in the housing, wherein the plurality of holes allow fluid communication between an inner diameter of the housing and an exterior of the housing, wherein the reactive material is expandable to close the plurality of holes.

Abstract: Improved casing strings, and methods of using improved casing strings in subterranean cementing operations, are provided. An example of an apparatus is a pipe string comprising at least one pipe section and a delivery system of an activator. Another example of an apparatus is a pipe string comprising at least one pipe section and a delivery system of a set retarder. An example of a method is a method of cementing in a subterranean formation. Other examples of methods are methods of cementing in a subterranean formation comprising a well bore.

Abstract: Improved casing strings, and methods of using improved casing strings in subterranean cementing operations, are provided. An example of an apparatus is a pipe string comprising at least one pipe section and a delivery system of an activator. Another example of an apparatus is a pipe string comprising at least one pipe section and a delivery system of a set retarder. An example of a method is a method of cementing in a subterranean formation. Other examples of methods are methods of cementing in a subterranean formation comprising a well bore.

Abstract: Improved casing strings, and methods of using improved casing strings in subterranean cementing operations, are provided. An example of an apparatus is a pipe string comprising at least one pipe section and a delivery system of an activator. Another example of an apparatus is a pipe string comprising at least one pipe section and a delivery system of a set retarder. An example of a method is a method of cementing in a subterranean formation. Other examples of methods are methods of cementing in a subterranean formation comprising a well bore.

Abstract: Methods and systems for reverse-circulation cementing in subterranean formations are provided. An example of a method is a method of cementing casing in a subterranean well bore, comprising inserting a casing into the well bore, the casing comprising a casing shoe; equipping the casing with a well head, and a casing inner diameter pressure indicator; flowing an equilibrium fluid into the well bore; flowing a cement composition into the well bore after the equilibrium fluid; determining from the well-bore pressure indicator when the well bore pressure has reached a desired value; discontinuing the flow of cement composition into the well bore upon determining that the well bore pressure has reached a desired value; and permitting the cement composition to set in the subterranean formation. Examples of systems include systems for cementing casing in a well bore.

Abstract: Methods and systems for reverse-circulation cementing in subterranean formations are provided. An example of a method is a method of cementing casing in a subterranean well bore, comprising inserting a casing into the well bore, the casing comprising a casing shoe; equipping the casing with a well head, and a casing inner diameter pressure indicator; flowing an equilibrium fluid into the well bore; flowing a cement composition into the well bore after the equilibrium fluid; determining from the well-bore pressure indicator when the well bore pressure has reached a desired value; discontinuing the flow of cement composition into the well bore upon determining that the well bore pressure has reached a desired value; and permitting the cement composition to set in the subterranean formation. Examples of systems include systems for cementing casing in a well bore.

Abstract: A method having the following steps: running a circulation valve comprising a reactive material into the well bore on the casing; reverse-circulating an activator material in the well bore until the activator material contacts the reactive material of the circulation valve; reconfiguring the circulation valve by contact of the activator material with the reactive material; and reverse-circulating a cement composition in the well bore until the reconfigured circulation valve decreases flow of the cement composition. A circulation valve for cementing casing in a well bore, the valve having: a valve housing connected to the casing and comprising a reactive material; a plurality of holes in the housing, wherein the plurality of holes allow fluid communication between an inner diameter of the housing and an exterior of the housing, wherein the reactive material is expandable to close the plurality of holes.

Abstract: Methods and systems for reverse-circulation cementing in subterranean formations are provided. An example of a method is a method of cementing casing in a subterranean well bore, comprising inserting a casing into the well bore, the casing comprising a casing shoe; equipping the casing with a well head, and a casing inner diameter pressure indicator; flowing an equilibrium fluid into the well bore; flowing a cement composition into the well bore after the equilibrium fluid; determining from the well-bore pressure indicator when the well bore pressure has reached a desired value; discontinuing the flow of cement composition into the well bore upon determining that the well bore pressure has reached a desired value; and permitting the cement composition to set in the subterranean formation. Examples of systems include systems for cementing casing in a well bore.

Abstract: Improved casing strings, and methods of using improved casing strings in subterranean cementing operations, are provided. An example of an apparatus is a pipe string comprising at least one pipe section and a delivery system of an activator. Another example of an apparatus is a pipe string comprising at least one pipe section and a delivery system of a set retarder. An example of a method is a method of cementing in a subterranean formation. Other examples of methods are methods of cementing in a subterranean formation comprising a well bore.

Abstract: Methods and systems for cementing casing in well bores drilled in subterranean formations, and more particularly, methods and systems for cementing casing in a well bore without surface casing or a well head are provided. A method provided herein may comprise sealing an annulus at the mouth of the well bore with a seal; pumping a cement composition into the annulus through the seal; and taking circulation fluid returns from the inner diameter of the casing. A system provided herein may comprise a seal of an annulus at the mouth of the well bore; a cement composition pump fluidly connected to the annulus through the seal; and a coupling connected to the exposed end of the casing for taking circulation fluid returns from the inner diameter of the casing.

Abstract: Improved casing strings, and methods of using improved casing strings in subterranean operations, are provided. An example of a method is a method of cementing a pipe string in a subterranean formation. Another example of a method is a method of cementing a pipe string in a well bore. An example of an apparatus is an improved pipe string comprising at least one pipe section; and a delivery system of an activator; wherein the delivery system of an activator is disposed adjacent an outer surface of the at least one pipe section.

Abstract: A method of initiating fluid circulation in a well bore through a casing inner diameter and an annulus outside the casing, the method having the following steps: inducing an increase in the annulus fluid pressure; flowing cement composition into the annulus at the top of the well bore; maintaining a difference in pressure between the fluid pressure of the casing inner diameter and the fluid pressure of the annulus until enough cement composition has entered the annulus to drive fluid circulation by the added cement composition weight.

Abstract: Methods of combating production problems in wells containing defective gravel packs are provided. The methods basically comprise forming at least one perforation in the well bore extending from the well bore through the defective gravel pack and into the producing formation, forming at least one fracture containing proppant material in the formation communicating with the perforation and consolidating the proppant material in the fracture.